Tüm alıştırma soruları

2789 soru

Soru 1561Soru

Although many historians credit Johannes Gutenberg with the invention of movable type in Europe, the technology had already been developed in Asia centuries earlier. In 1041, Chinese alchemist Bi Sheng created the world’s first known movable type system ______ he used individual clay pieces for each character, which could then be rearranged and inked to print multiple pages.

Which choice completes the text so that it conforms to the conventions of Standard English?

Cevabı ve açıklamayı göster

Cevap: : he

Cevap

The correct answer is the option containing a colon followed by the pronoun 'he'. A colon is appropriate here because it separates two independent clauses, where the second clause directly explains or expands on the first.
The option containing the colon followed by the pronoun 'he' is correct because the clause before the punctuation mark is independent, and the clause after it is also independent and serves to explain or elaborate on the first clause. In Standard English conventions, a colon is a proper way to link an independent clause to an explanatory clause.

Adım Adım Çözüm

1
Analyze the structure of the clauses before and after the blank.
The clause preceding the blank ('In 1041, Chinese alchemist Bi Sheng created the world’s first known movable type system') is independent. The clause following the blank ('he used individual clay pieces...') is also independent and explains the first clause.
Identifying the clause types helps determine which punctuation marks are grammatically permissible to link them.
2
Evaluate the grammatical correctness of each punctuation option.
A colon is correct because the first clause is independent and the second clause explains it. A comma alone creates a comma splice. A semicolon cannot be followed by a dependent participial phrase like 'using'. Leaving no punctuation creates a run-on sentence.
Standard English conventions dictate that a colon must be preceded by an independent clause and can link to an explanatory clause, while commas and semicolons have stricter clause-boundary rules.

Anahtar Kavram

Using colons, semicolons, and dashes to link clauses or phrases
Soru 1562Soru

Discovered in the late twentieth century near deep-sea hydrothermal vents on the ocean floor, giant tube worms lack a mouth, gut, or digestive tract. Instead, each individual worm relies entirely on millions of symbiotic bacteria housed within the ______ specialized organ, known as the trophosome, which converts hydrogen sulfide into nutrients.

Which choice completes the text so that it conforms to the conventions of Standard English?

Cevabı ve açıklamayı göster

Cevap: worm's

Cevap

worm's
The correct answer is the singular possessive form 'worm's'. The sentence refers to the 'specialized organ' belonging to 'each individual worm'. Because 'each individual' is singular, the possessive noun modifying 'specialized organ' must also be singular. Adding an apostrophe followed by 's' to the singular noun 'worm' correctly indicates this singular possessive relationship.

Adım Adım Çözüm

1
Analyze the context to determine the relationship between the target noun and the noun phrase that follows it.
The target noun modifies 'specialized organ', indicating ownership or possession of the organ by the worm. Therefore, a possessive form of the noun is required.
Possessive nouns are used to show ownership or association with a following noun.
2
Determine whether the possessive noun should be singular or plural by looking for clues in the sentence.
The phrase 'each individual worm' establishes that the sentence is referring to a single organism. Thus, a singular possessive noun is required.
Singular subjects require singular possessive modifiers to maintain grammatical agreement.
3
Select the correct spelling of the singular possessive form of 'worm'.
The singular possessive form is created by adding an apostrophe and 's' to the end of the singular noun: 'worm's'.
Standard English conventions dictate adding '-\'s' to a singular noun to indicate possession.

Anahtar Kavram

Plural and Possessive Nouns
Soru 1563Soru

A logistics company uses a delivery drone to transport two types of packages. Let xx represent the number of Type A packages and yy represent the number of Type B packages in a single flight. The drone can carry at most 12 packages in total. Additionally, to balance the drone, the total weight of the cargo must be at least 15 pounds. Each Type A package weighs 2 pounds, and each Type B package weighs 1 pound. Which of the following combinations of Type A and Type B packages is a viable shipment for the drone?

Cevabı ve açıklamayı göster

Cevap: 5 Type A packages and 6 Type B packages

Cevap

5 Type A packages and 6 Type B packages
The correct combination of 5 Type A packages and 6 Type B packages satisfies all system requirements. The total package count of 11 is less than or equal to the drone's limit of 12 packages (5+6125 + 6 \leq 12). Furthermore, the total weight of 16 pounds meets the minimum balance requirement of 15 pounds (2(5)+6152(5) + 6 \geq 15).

Adım Adım Çözüm

1
Write the system of linear inequalities that represents the given constraints.
The capacity constraint is x+y12x + y \leq 12, and the weight constraint is 2x+y152x + y \geq 15, where xx and yy are non-negative integers.
To define the mathematical boundaries for a valid shipment.
2
Substitute the package counts from the correct combination into both inequalities to verify they are satisfied.
For 5 Type A packages (x=5x = 5) and 6 Type B packages (y=6y = 6):
- Package count: 5+6=11125 + 6 = 11 \leq 12 (True)
- Cargo weight: 2(5)+6=16152(5) + 6 = 16 \geq 15 (True)
To confirm that the chosen combination satisfies all system requirements.

Anahtar Kavram

Systems of Linear Inequalities in Two Variables
Tahmini Süre:1m 30s
Soru 1564Soru

A coffee shop sells two sizes of bagged coffee: a standard bag and a deluxe bag. On Monday, the shop sold 88 standard bags and 55 deluxe bags for a total of $108\$108. On Tuesday, the shop sold 66 standard bags and 1010 deluxe bags for a total of $156\$156. What is the price, in dollars, of one deluxe bag of coffee?

Cevabı ve açıklamayı göster

Cevap: 12

Cevap

The price of one deluxe bag of coffee is 1212 dollars.
By setting up a system of equations, we represent the total cost on Monday as 8s+5d=1088s + 5d = 108 and on Tuesday as 6s+10d=1566s + 10d = 156. Multiplying the first equation by 22 gives 16s+10d=21616s + 10d = 216. Subtracting the second equation yields 10s=6010s = 60, so s=6s = 6. Substituting s=6s = 6 into the first equation yields 8(6)+5d=1088(6) + 5d = 108, which simplifies to 48+5d=10848 + 5d = 108, then 5d=605d = 60, and finally d=12d = 12.

Adım Adım Çözüm

1
Define the variables and write the system of equations.
Let ss be the price of a standard bag and dd be the price of a deluxe bag. The system is:
8s+5d=1088s + 5d = 108
6s+10d=1566s + 10d = 156
To translate the word problem into mathematical equations.
2
Multiply the first equation by 22 to align the coefficients of dd.
16s+10d=21616s + 10d = 216
To prepare for elimination of the variable dd.
3
Subtract the second equation from the new equation to solve for ss.
10s=6010s = 60, which simplifies to s=6s = 6.
To eliminate dd and find the price of a standard bag.
4
Substitute the value of ss back into one of the original equations to solve for dd.
8(6)+5d=108    48+5d=108    5d=60    d=128(6) + 5d = 108 \implies 48 + 5d = 108 \implies 5d = 60 \implies d = 12.
To find the price of a deluxe bag.

Anahtar Kavram

Solving systems of linear equations using the elimination method.
Tahmini Süre:1m 30s
Soru 1565Soru

What form of the noun 'machine' correctly completes the blank in the passage?

Aşağıdaki boşlukları doldurun

In 1843, mathematician Ada Lovelace published extensive notes on Charles Babbage's proposed mechanical computer, which was known as the Analytical Engine. While Babbage focused primarily on calculation, Lovelace realized that the device could do more than just compute numbers; she envisioned the potential to process symbols and music, effectively writing the world's first computer program.
Cevabı ve açıklamayı göster

Cevap

machine's
The singular possessive noun 'machine's' is correct because the context refers to a single machine (the Analytical Engine) and shows ownership of the noun 'potential' that follows the blank.

Adım Adım Çözüm

1
Determine if the noun should be singular or plural based on the context.
The passage refers to a single device (the Analytical Engine / the device), indicating that the singular form of the noun 'machine' is required.
The context refers back to Charles Babbage's proposed mechanical computer, which is singular.
2
Determine if the noun needs to be possessive.
The noun modifies the noun 'potential,' indicating that the potential belongs to the machine. Therefore, the possessive case is required.
A noun modifying another noun to show ownership or association must be in the possessive case.
3
Form the singular possessive spelling of 'machine'.
Add an apostrophe followed by the letter 's' to the singular noun 'machine' to form 'machine's'.
Singular possessive nouns are formed by adding "'s" to the singular noun.

Anahtar Kavram

Plural and Possessive Nouns and Pronouns
Tahmini Süre:1m 0s
Soru 1566Soru

An exponential function gg is defined by g(x)=pqxg(x) = p \cdot q^x, where pp and qq are positive constants. If g(12)=6g\left(\frac{1}{2}\right) = 6 and g(32)=54g\left(\frac{3}{2}\right) = 54, what is the value of g(2)g(2)?

Cevabı ve açıklamayı göster

Cevap: 162

Cevap

162
The correct answer is 162. Substituting the coordinates into the function gives the system pq1/2=6p \cdot q^{1/2} = 6 and pq3/2=54p \cdot q^{3/2} = 54. Dividing the second equation by the first yields q=9q = 9. Substituting q=9q = 9 into the first equation yields p3=6p \cdot 3 = 6, so p=2p = 2. The complete function is g(x)=29xg(x) = 2 \cdot 9^x, and evaluating g(2)g(2) gives 281=1622 \cdot 81 = 162.

Adım Adım Çözüm

1
Substitute the given values into the function definition to set up a system of equations.
pq1/2=6p \cdot q^{1/2} = 6 and pq3/2=54p \cdot q^{3/2} = 54
To represent the given coordinate relationships using the exponential model parameters.
2
Divide the equation for g(32)g\left(\frac{3}{2}\right) by the equation for g(12)g\left(\frac{1}{2}\right) to eliminate pp and solve for qq.
q=9q = 9
Using the exponent quotient rule, q3/2q1/2=q3/21/2=q1=q\frac{q^{3/2}}{q^{1/2}} = q^{3/2 - 1/2} = q^1 = q. Dividing the constants gives 546=9\frac{54}{6} = 9.
3
Substitute q=9q = 9 back into the first equation and solve for pp.
p=2p = 2
Evaluating the fractional exponent gives 91/2=9=39^{1/2} = \sqrt{9} = 3. Substituting this in yields 3p=63p = 6, which simplifies to p=2p = 2.
4
Evaluate the completed exponential function g(x)=29xg(x) = 2 \cdot 9^x at x=2x = 2.
162
Calculating g(2)=292=281=162g(2) = 2 \cdot 9^2 = 2 \cdot 81 = 162 solves for the target value.

Anahtar Kavram

Solving a system of exponential equations using fractional exponent rules and base evaluation.
Soru 1567Soru

A geophysicist models the temperature, TT, in degrees Celsius (C^\circ\text{C}), of a rock layer during a deep-crust drilling project using a linear function of the depth, dd, in kilometers (km\text{km}), below the surface. According to the model, for every increase in depth of 0.8 km0.8\text{ km}, the temperature of the rock increases by 22C22^\circ\text{C}. At a depth of 2.4 km2.4\text{ km}, the temperature of the rock is 81C81^\circ\text{C}. According to the model, at what depth, in kilometers, will the temperature of the rock be 114C114^\circ\text{C}?

Cevabı ve açıklamayı göster

Cevap: 3.6

Cevap

The temperature of the rock will reach 114C114^\circ\text{C} at a depth of 3.63.6 kilometers.
The correct answer is 3.63.6. The rate of change of temperature with depth is 22C0.8 km=27.5C/km\frac{22^\circ\text{C}}{0.8\text{ km}} = 27.5^\circ\text{C/km}. The linear relationship between temperature TT and depth dd can be modeled by T=27.5d+T0T = 27.5d + T_0, where T0T_0 is the temperature at the surface. Substituting the known values d=2.4d = 2.4 and T=81T = 81 into the model gives 81=27.5(2.4)+T081 = 27.5(2.4) + T_0, which simplifies to 81=66+T081 = 66 + T_0. Solving for T0T_0 yields T0=15T_0 = 15. Thus, the model is T=27.5d+15T = 27.5d + 15. To find the depth when the temperature is 114C114^\circ\text{C}, substitute T=114T = 114 into the model: 114=27.5d+15114 = 27.5d + 15. Subtracting 1515 from both sides gives 99=27.5d99 = 27.5d, and dividing by 27.527.5 yields d=3.6d = 3.6.

Adım Adım Çözüm

1
Find the rate of change (slope) of the temperature with respect to depth.
The slope is 27.5C/km27.5^\circ\text{C/km}.
The temperature increases by 22C22^\circ\text{C} for every 0.8 km0.8\text{ km} of depth, so the rate of change is 22C0.8 km=27.5C/km\frac{22^\circ\text{C}}{0.8\text{ km}} = 27.5^\circ\text{C/km}.
2
Set up a linear model and find the surface temperature (y-intercept).
The linear model is T=27.5d+15T = 27.5d + 15.
Using the slope-intercept form T=md+T0T = md + T_0 and substituting the given values d=2.4d = 2.4 and T=81T = 81 gives 81=27.5(2.4)+T081 = 27.5(2.4) + T_0, which simplifies to 81=66+T081 = 66 + T_0, so T0=15T_0 = 15.
3
Substitute the target temperature into the linear model and solve for the target depth.
d=3.6d = 3.6
Substitute T=114T = 114 into the equation T=27.5d+15T = 27.5d + 15 to get 114=27.5d+15114 = 27.5d + 15. Subtracting 1515 from both sides gives 99=27.5d99 = 27.5d. Dividing both sides by 27.527.5 yields d=3.6d = 3.6.

Anahtar Kavram

Interpreting slope and solving for values in a linear relationship context.

Alternatif Yöntem

Find the required temperature increase: 114C81C=33C114^\circ\text{C} - 81^\circ\text{C} = 33^\circ\text{C}. Set up a proportion using the rate of 22C22^\circ\text{C} increase per 0.8 km0.8\text{ km} to find the change in depth Δd\Delta d: 33CΔd=22C0.8 km    Δd=33×0.822=1.2 km\frac{33^\circ\text{C}}{\Delta d} = \frac{22^\circ\text{C}}{0.8\text{ km}} \implies \Delta d = \frac{33 \times 0.8}{22} = 1.2\text{ km}. Add this change in depth to the initial depth to find the final depth: 2.4+1.2=3.6 km2.4 + 1.2 = 3.6\text{ km}.
Tahmini Süre:2m 0s
Soru 1568Soru

A radioactive substance decays according to the equation N(t)=N0(12)t8N(t) = N_0 \left(\frac{1}{2}\right)^{\frac{t}{8}}, where N(t)N(t) is the amount of the substance remaining after tt days, and N0N_0 is the initial amount. If the substance decays to 116\frac{1}{16} of its initial amount in dd days, what is the value of dd?

Cevabı ve açıklamayı göster

Cevap: 32

Cevap

32
The correct answer is 32. The remaining amount of the substance is given as 116\frac{1}{16} of the initial amount, so N(d)N0=116\frac{N(d)}{N_0} = \frac{1}{16}. Substituting dd for tt in the decay formula yields (12)d8=116\left(\frac{1}{2}\right)^{\frac{d}{8}} = \frac{1}{16}. Since 116=(12)4\frac{1}{16} = \left(\frac{1}{2}\right)^4, we can set the exponents equal to each other: d8=4\frac{d}{8} = 4. Solving for dd gives d=32d = 32.

Adım Adım Çözüm

1
Set up the equation for the remaining fraction of the substance.
N(d)N0=116\frac{N(d)}{N_0} = \frac{1}{16}
The problem states the substance decays to 116\frac{1}{16} of its initial amount N0N_0 in dd days.
2
Substitute the given decay formula into the equation.
(12)d8=116\left(\frac{1}{2}\right)^{\frac{d}{8}} = \frac{1}{16}
By replacing tt with dd in the formula N(t)N0=(12)t8\frac{N(t)}{N_0} = \left(\frac{1}{2}\right)^{\frac{t}{8}}, we get the expression for the remaining fraction.
3
Rewrite 116\frac{1}{16} as a power with base 12\frac{1}{2} to solve for the exponent.
(12)4=116\left(\frac{1}{2}\right)^4 = \frac{1}{16}
Since 24=162^4 = 16, the fraction 116\frac{1}{16} is equivalent to (12)4\left(\frac{1}{2}\right)^4.
4
Equate the exponents and solve for dd.
d8=4    d=32\frac{d}{8} = 4 \implies d = 32
Since the bases are equal, their exponents must be equal. Multiplying both sides by 8 isolates dd.

Anahtar Kavram

Solving exponential equations by equating bases
Soru 1569Soru

In the system of equations below, xx and yy are real numbers.

4x8y=1284^x \cdot 8^y = 128
9x3y=2439^x \cdot 3^y = 243

What is the value of xx?

Cevabı ve açıklamayı göster

Cevap: 2

Cevap

The value of xx is 22.
To solve the system of equations, express all terms in each equation using common bases. In the first equation, 4x8y=1284^x \cdot 8^y = 128 can be written as (22)x(23)y=27(2^2)^x \cdot (2^3)^y = 2^7, which simplifies to 22x+3y=272^{2x+3y} = 2^7, meaning 2x+3y=72x + 3y = 7. In the second equation, 9x3y=2439^x \cdot 3^y = 243 can be written as (32)x3y=35(3^2)^x \cdot 3^y = 3^5, which simplifies to 32x+y=353^{2x+y} = 3^5, meaning 2x+y=52x + y = 5. Subtracting the two equations gives (2x+3y)(2x+y)=75    2y=2    y=1(2x + 3y) - (2x + y) = 7 - 5 \implies 2y = 2 \implies y = 1. Substituting y=1y = 1 back into 2x+y=52x + y = 5 gives 2x+1=5    2x=4    x=22x + 1 = 5 \implies 2x = 4 \implies x = 2.

Adım Adım Çözüm

1
Rewrite the first equation using a common base of 2.
2x+3y=72x + 3y = 7
By converting 4x4^x to (22)x=22x(2^2)^x = 2^{2x}, 8y8^y to (23)y=23y(2^3)^y = 2^{3y}, and 128128 to 272^7, we can equate the exponents: 2x+3y=72x + 3y = 7.
2
Rewrite the second equation using a common base of 3.
2x+y=52x + y = 5
By converting 9x9^x to (32)x=32x(3^2)^x = 3^{2x}, keeping 3y3^y, and converting 243243 to 353^5, we can equate the exponents: 2x+y=52x + y = 5.
3
Solve the system of linear equations for yy.
y=1y = 1
Subtracting 2x+y=52x + y = 5 from 2x+3y=72x + 3y = 7 eliminates xx, leaving 2y=22y = 2, which gives y=1y = 1.
4
Substitute y=1y = 1 into one of the linear equations to solve for xx.
x=2x = 2
Substituting y=1y = 1 into 2x+y=52x + y = 5 yields 2x+1=52x + 1 = 5, which simplifies to 2x=42x = 4, so x=2x = 2.

Anahtar Kavram

Solving systems of exponential equations by converting to a common base and applying exponent laws.
Soru 1570Soru

Which of the following is equivalent to the expression 3x25x4x2\frac{3x^2 - 5x - 4}{x - 2} for all x2x \neq 2?

Cevabı ve açıklamayı göster

Cevap: 3x+12x23x + 1 - \frac{2}{x - 2}

Cevap

3x+12x23x + 1 - \frac{2}{x - 2}
The correct answer represents the equivalent expression obtained by performing polynomial division on the rational expression. Dividing the numerator 3x25x43x^2 - 5x - 4 by the denominator x2x - 2 yields a quotient of 3x+13x + 1 and a remainder of 2-2. This can be written in the form of the quotient plus the remainder over the divisor, resulting in 3x+12x23x + 1 - \frac{2}{x - 2}.

Adım Adım Çözüm

1
Divide the leading term of the numerator, 3x23x^2, by the leading term of the denominator, xx.
The first term of the quotient is 3x3x.
This starts the polynomial long division process.
2
Multiply 3x3x by the divisor (x2)(x - 2) and subtract the result from the numerator.
(3x25x4)(3x26x)=x4(3x^2 - 5x - 4) - (3x^2 - 6x) = x - 4.
Subtracting the multiplied term helps find the remainder of the first division step.
3
Divide the leading term of the remaining expression, xx, by the leading term of the divisor, xx.
The second term of the quotient is 11.
To continue the division process with the remaining terms.
4
Multiply 11 by the divisor (x2)(x - 2) and subtract the result from x4x - 4.
(x4)(x2)=2(x - 4) - (x - 2) = -2.
This step determines the final remainder of 2-2 because the degree of the remainder is now less than the degree of the divisor.
5
Express the final result as the sum of the quotient and the remainder divided by the divisor.
3x+12x23x + 1 - \frac{2}{x - 2}
To construct the equivalent algebraic expression.

Anahtar Kavram

Equivalent Algebraic Expressions
Soru 1571Soru

In the xyxy-plane, the graph of the quadratic function f(x)=x2+bx+cf(x) = -x^2 + bx + c has a vertex at (h,k)(h, k). The graph of ff is translated 44 units to the right and 55 units up to form the graph of a quadratic function gg. If the graph of gg passes through the point (1,16)(1, 16) and has a yy-intercept of 1313, what is the value of kk?

Cevabı ve açıklamayı göster

Cevap: 12

Cevap

The value of kk is 1212.
By writing the function in vertex form as f(x)=(xh)2+kf(x) = -(x-h)^2 + k, we can apply the transformations directly. Translating the graph 44 units to the right and 55 units up gives the function g(x)=f(x4)+5=(xh4)2+k+5g(x) = f(x-4) + 5 = -(x-h-4)^2 + k+5. Using the given points g(0)=13g(0) = 13 and g(1)=16g(1) = 16, we set up a system of equations: (h+4)2+k+5=13-(h+4)^2 + k+5 = 13 and (h+3)2+k+5=16-(h+3)^2 + k+5 = 16. Solving these simultaneously gives h=2h = -2 and k=12k = 12.

Adım Adım Çözüm

1
Write the function f(x)f(x) in vertex form.
f(x)=(xh)2+kf(x) = -(x-h)^2 + k
Since the leading coefficient of f(x)=x2+bx+cf(x) = -x^2 + bx + c is 1-1, the vertex form must have a coefficient of 1-1.
2
Represent the translated function g(x)g(x).
g(x)=(xh4)2+k+5g(x) = -(x-h-4)^2 + k+5
Translating a function f(x)f(x) by 44 units to the right and 55 units up yields g(x)=f(x4)+5g(x) = f(x-4) + 5.
3
Use the yy-intercept of g(x)g(x) to write the first equation.
k(h+4)2=8k - (h+4)^2 = 8
The yy-intercept is the value of the function at x=0x = 0, so g(0)=13g(0) = 13.
4
Use the point (1,16)(1, 16) on g(x)g(x) to write the second equation.
k(h+3)2=11k - (h+3)^2 = 11
The graph passing through (1,16)(1, 16) means g(1)=16g(1) = 16.
5
Solve the system of equations for hh and kk.
h=2h = -2 and k=12k = 12
Equating the expressions for kk gives (h+4)2+8=(h+3)2+11(h+4)^2 + 8 = (h+3)^2 + 11, which simplifies to 2h=42h = -4, so h=2h = -2. Substituting h=2h = -2 into k=(h+4)2+8k = (h+4)^2 + 8 yields k=12k = 12.

Anahtar Kavram

Translating quadratic functions and solving systems of quadratic equations.
Soru 1572Soru

In the inequality 3(42x)5(xc)73(4 - 2x) - 5(x - c) \geq -7, where cc is a constant, the solution set consists of all values of xx such that x3x \leq 3. What is the value of cc?

Cevabı ve açıklamayı göster

Cevap: 2.8

Cevap

2.8
To find the value of cc, first simplify the inequality 3(42x)5(xc)73(4 - 2x) - 5(x - c) \geq -7 by expanding the terms using the distributive property, which yields 126x5x+5c712 - 6x - 5x + 5c \geq -7. Combining like terms gives 11x+12+5c7-11x + 12 + 5c \geq -7. Next, isolate the variable term by subtracting 1212 and 5c5c from both sides to obtain 11x195c-11x \geq -19 - 5c. Dividing both sides of the inequality by 11-11 and reversing the inequality sign results in x19+5c11x \leq \frac{19 + 5c}{11}. Given that the solution set consists of all values of xx such that x3x \leq 3, the boundary value 19+5c11\frac{19 + 5c}{11} must equal 33. Solving the equation 19+5c11=3\frac{19 + 5c}{11} = 3 gives 19+5c=3319 + 5c = 33, which simplifies to 5c=145c = 14 and results in c=2.8c = 2.8.

Adım Adım Çözüm

1
Distribute the constants on the left side of the inequality.
126x5x+5c712 - 6x - 5x + 5c \geq -7
Applying the distributive property simplifies the parentheses.
2
Combine the variable terms.
11x+12+5c7-11x + 12 + 5c \geq -7
Grouping like terms simplifies the inequality.
3
Subtract 1212 and 5c5c from both sides of the inequality.
11x195c-11x \geq -19 - 5c
This isolates the term containing xx.
4
Divide both sides by 11-11 and reverse the direction of the inequality.
x19+5c11x \leq \frac{19 + 5c}{11}
Dividing by a negative number requires flipping the inequality sign to maintain equivalence.
5
Set the algebraic boundary 19+5c11\frac{19 + 5c}{11} equal to the given boundary value of 33 and solve for cc.
c=2.8c = 2.8
Since the solution set is x3x \leq 3, the boundary values must be equivalent.

Anahtar Kavram

Solving multi-step linear inequalities in one variable containing parameters.
Soru 1573Soru

The graph of the equation ax+by=24ax + by = 24, where aa and bb are constants, is a line in the xyxy-plane. If this line passes through the points (2,9)(2, 9) and (6,3)(6, 3), what is the value of a+ba + b?

Cevabı ve açıklamayı göster

Cevap: 5

Cevap

The value of a+ba + b is 55.
Substituting the coordinates of the two points (2,9)(2, 9) and (6,3)(6, 3) into the given linear equation ax+by=24ax + by = 24 yields a system of two equations: 2a+9b=242a + 9b = 24 and 6a+3b=246a + 3b = 24. Simplifying the second equation gives 2a+b=82a + b = 8, which means b=82ab = 8 - 2a. Substituting this expression for bb into the first equation yields 2a+9(82a)=242a + 9(8 - 2a) = 24, which simplifies to 16a=48-16a = -48, or a=3a = 3. Plugging a=3a = 3 back into b=82ab = 8 - 2a gives b=2b = 2. Thus, the value of a+ba + b is 3+2=53 + 2 = 5.

Adım Adım Çözüm

1
Substitute the point (2,9)(2, 9) into the equation ax+by=24ax + by = 24.
2a+9b=242a + 9b = 24
Since the line passes through the point (2,9)(2, 9), the coordinates must satisfy the equation of the line.
2
Substitute the point (6,3)(6, 3) into the equation ax+by=24ax + by = 24.
6a+3b=246a + 3b = 24
Since the line passes through the point (6,3)(6, 3), the coordinates must satisfy the equation of the line.
3
Solve the system of equations for aa and bb.
a=3a = 3 and b=2b = 2
To find the values of the constants aa and bb, we solve the linear system: (1) 2a+9b=242a + 9b = 24 and (2) 6a+3b=246a + 3b = 24. Dividing the second equation by 3 gives 2a+b=82a + b = 8, or b=82ab = 8 - 2a. Substituting this into the first equation gives 2a+9(82a)=24    2a+7218a=24    16a=48    a=32a + 9(8 - 2a) = 24 \implies 2a + 72 - 18a = 24 \implies -16a = -48 \implies a = 3. Then, b=82(3)=2b = 8 - 2(3) = 2.
4
Add the values of aa and bb.
a+b=5a + b = 5
The question asks for the value of a+ba + b.

Anahtar Kavram

Solving systems of linear equations derived from coordinate substitution in a two-variable linear equation.
Tahmini Süre:1m 30s
Soru 1574Soru

For a constant kk, the inequality 2(3x)k(x+5)>42(3 - x) - k(x + 5) > 4 has the solution set x<3x < -3. What is the value of kk?

Cevabı ve açıklamayı göster

Cevap: 44

Cevap

4
The correct answer is 44. Expanding the inequality 2(3x)k(x+5)>42(3 - x) - k(x + 5) > 4 gives 62xkx5k>46 - 2x - kx - 5k > 4. Grouping the xx terms yields (2k)x>5k2(-2 - k)x > 5k - 2. Because the given solution set is x<3x < -3, the inequality sign must flip, indicating that the coefficient 2k-2 - k is negative. Dividing by this negative coefficient yields x<5k22kx < \frac{5k - 2}{-2 - k}. Setting the boundary expression equal to the boundary of the solution set gives 5k22k=3\frac{5k - 2}{-2 - k} = -3. Multiplying both sides by 2k-2 - k results in 5k2=6+3k5k - 2 = 6 + 3k. Subtracting 3k3k and adding 22 to both sides gives 2k=82k = 8, which simplifies to k=4k = 4.

Adım Adım Çözüm

1
Distribute the constants in the inequality
62xkx5k>46 - 2x - kx - 5k > 4
To clear parentheses and prepare to group terms.
2
Group the xx terms and constant terms
(2k)x>5k2(-2 - k)x > 5k - 2
To isolate the variable xx on one side of the inequality.
3
Divide by the coefficient of xx and flip the inequality direction
x<5k22kx < \frac{5k - 2}{-2 - k}
Since the solution set is x<3x < -3, the direction of the inequality must flip from >> to <<, meaning the coefficient 2k-2 - k must be negative.
4
Set the boundary value equal to 3-3 and solve for kk
k=4k = 4
The boundary of the solution set must be equal to 3-3. Solving 5k22k=3\frac{5k - 2}{-2 - k} = -3 yields 5k2=6+3k5k - 2 = 6 + 3k, which simplifies to 2k=82k = 8, so k=4k = 4.

Anahtar Kavram

Solving linear inequalities in one variable with symbolic coefficients, accounting for direction flips when dividing by negative quantities.
Soru 1575Soru
(x4)2+(y+1)2=18x+y=k\begin{aligned} (x - 4)^2 + (y + 1)^2 &= 18 \\ x + y &= k \end{aligned}

In the system of equations above, kk is a constant. If the system has exactly one real solution, what is the sum of all possible values of kk?

Cevabı ve açıklamayı göster

Cevap: 6

Cevap

The sum of all possible values of kk is 66.
The system of equations has exactly one real solution when the line is tangent to the circle. The circle (x4)2+(y+1)2=18(x - 4)^2 + (y + 1)^2 = 18 has center (4,1)(4, -1) and radius 18=32\sqrt{18} = 3\sqrt{2}. The distance from the center of the circle to the line x+yk=0x + y - k = 0 is given by 41k12+12=3k2\frac{|4 - 1 - k|}{\sqrt{1^2 + 1^2}} = \frac{|3 - k|}{\sqrt{2}}. Setting this distance equal to the radius yields 3k2=32    3k=6\frac{|3 - k|}{\sqrt{2}} = 3\sqrt{2} \implies |3 - k| = 6. Solving this equation gives k=9k = 9 and k=3k = -3. The sum of these possible values is 9+(3)=69 + (-3) = 6.

Adım Adım Çözüm

1
Relate the algebraic condition of having exactly one solution to the geometric relationship between the circle and the line.
The line must be tangent to the circle, meaning the perpendicular distance from the center of the circle to the line must equal the radius of the circle.
A system consisting of a circle and a line has exactly one real solution if and only if the line is tangent to the circle.
2
Identify the center and radius of the circle from the equation (x4)2+(y+1)2=18(x - 4)^2 + (y + 1)^2 = 18.
The center of the circle is (4,1)(4, -1) and the radius is r=18=32r = \sqrt{18} = 3\sqrt{2}.
The standard form of a circle equation is (xh)2+(yk)2=r2(x - h)^2 + (y - k)^2 = r^2, where (h,k)(h, k) is the center and rr is the radius.
3
Express the line equation in standard form Ax+By+C=0Ax + By + C = 0 and set up the perpendicular distance formula.
The line equation is x+yk=0x + y - k = 0. The distance from the center (4,1)(4, -1) to the line is d=(1)(4)+(1)(1)k12+12=3k2d = \frac{|(1)(4) + (1)(-1) - k|}{\sqrt{1^2 + 1^2}} = \frac{|3 - k|}{\sqrt{2}}.
The perpendicular distance from a point (x0,y0)(x_0, y_0) to a line Ax+By+C=0Ax + By + C = 0 is given by d=Ax0+By0+CA2+B2d = \frac{|Ax_0 + By_0 + C|}{\sqrt{A^2 + B^2}}.
4
Set the distance equal to the radius of the circle and solve the absolute value equation for kk.
\frac{|3 - k|}{\sqrt{2}} = 3\sqrt{2} \implies |3 - k| = 6 .Thisyieldstwoequations:. This yields two equations: 3 - k = 6 \implies k = -3 ,and, and 3 - k = -6 \implies k = 9$.
Setting the distance equal to the radius ensures that the line is tangent to the circle, resulting in exactly one point of intersection.
5
Calculate the sum of all possible values of kk.
Sum = 3+9=6-3 + 9 = 6.
The question asks for the sum of all values of kk that satisfy the tangency condition.

Anahtar Kavram

Determining the relationship between a line and a circle in a system of equations by setting the perpendicular distance from the center of the circle equal to its radius.

Alternatif Yöntem

Substitute y=kxy = k - x into the circle equation to obtain a quadratic equation in xx: (x4)2+(kx+1)2=18(x - 4)^2 + (k - x + 1)^2 = 18. Expanding and combining like terms yields 2x22(k+5)x+(k2+2k1)=02x^2 - 2(k + 5)x + (k^2 + 2k - 1) = 0. For the system to have exactly one real solution, the discriminant Δ\Delta of this quadratic equation must be zero: Δ=[2(k+5)]24(2)(k2+2k1)=0\Delta = [-2(k + 5)]^2 - 4(2)(k^2 + 2k - 1) = 0. Simplifying this equation leads to 4(k2+10k+25)8(k2+2k1)=0    k26k27=04(k^2 + 10k + 25) - 8(k^2 + 2k - 1) = 0 \implies k^2 - 6k - 27 = 0. By Vieta's formulas, the sum of the solutions to this quadratic equation for kk is given by ba=61=6-\frac{b}{a} = -\frac{-6}{1} = 6.
Tahmini Süre:2m 30s
Soru 1576Soru

A system of equations consists of the quadratic function f(x)=x2+6x2f(x) = -x^2 + 6x - 2 and the linear function g(x)=2x+1g(x) = 2x + 1. If the graphs of ff and gg intersect at the points (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2) in the xyxy-plane, what is the value of y1+y2y_1 + y_2?

Cevabı ve açıklamayı göster

Cevap: 10

Cevap

10
By setting the two equations equal to each other, we obtain x2+6x2=2x+1-x^2 + 6x - 2 = 2x + 1. Rearranging terms to one side gives x24x+3=0x^2 - 4x + 3 = 0, which factors as (x1)(x3)=0(x-1)(x-3) = 0. The x-coordinates of the intersection points are x=1x = 1 and x=3x = 3. Substituting these into the linear equation gives the y-coordinates: for x=1x = 1, y=2(1)+1=3y = 2(1) + 1 = 3; for x=3x = 3, y=2(3)+1=7y = 2(3) + 1 = 7. Summing these y-coordinates gives 3+7=103 + 7 = 10.

Adım Adım Çözüm

1
Set the quadratic function equal to the linear function to find the x-coordinates of the intersection points.
x2+6x2=2x+1-x^2 + 6x - 2 = 2x + 1
At the points of intersection, the y-values of both functions must be equal.
2
Rearrange the equation into standard quadratic form and solve for xx by factoring.
x24x+3=0(x1)(x3)=0x=1 or x=3x^2 - 4x + 3 = 0 \Rightarrow (x - 1)(x - 3) = 0 \Rightarrow x = 1 \text{ or } x = 3
Factoring the quadratic equation gives the x-coordinates of the intersection points.
3
Substitute the x-coordinates back into the linear equation to find the corresponding y-coordinates.
For x1=1x_1 = 1, y1=2(1)+1=3y_1 = 2(1) + 1 = 3. For x2=3x_2 = 3, y2=2(3)+1=7y_2 = 2(3) + 1 = 7.
The linear equation g(x)=2x+1g(x) = 2x + 1 is simpler to use for finding the y-coordinates than the quadratic equation.
4
Sum the two y-coordinates.
y1+y2=3+7=10y_1 + y_2 = 3 + 7 = 10
The question asks for the sum of the y-coordinates of the intersection points.

Anahtar Kavram

Solving a system consisting of a linear equation and a quadratic equation by substitution or equating them.
Soru 1577Soru

Based on the grammar and context of the passage, what form of the noun 'dragonfly' correctly completes the blank?

Aşağıdaki boşlukları doldurun

Unlike most insects, which rely on simple muscle contractions to flap their wings, a dragonfly utilizes direct muscle attachments to control each wing independently. This unique anatomical feature allows the maneuverability to surpass that of almost any other aerial predator, enabling it to hover, fly backward, and change direction mid-flight with remarkable precision.
Cevabı ve açıklamayı göster

Cevap

dragonfly's
The singular possessive noun 'dragonfly's' correctly attributes the maneuverability to a single dragonfly. The singular context is established by the phrase 'a dragonfly' in the first sentence and the pronoun 'it' in the second sentence. To form a singular possessive, an apostrophe and an 's' must be added to the singular noun.

Adım Adım Çözüm

1
Analyze the context to determine if the noun should be singular or plural.
The passage introduces the subject in the singular form ('a dragonfly') and subsequently uses the singular pronoun 'it' ('enabling it to hover'). Therefore, the target noun must be singular.
Identifying the number of the noun ensures correct agreement with the surrounding context.
2
Determine if the noun requires a possessive form.
The noun modifies the resource 'maneuverability', indicating that the maneuverability belongs to the dragonfly. Thus, a possessive case is required.
Identifying the case of the noun determines the correct punctuation structure.
3
Form the singular possessive noun.
Adding an apostrophe followed by 's' to the singular noun 'dragonfly' yields 'dragonfly's'.
Applying standard English orthography rules for singular possessives provides the correct spelling.

Anahtar Kavram

Plural and Possessive Nouns
Tahmini Süre:1m 0s
Soru 1578Soru

The quadratic function ff is defined by f(x)=3(x2)2+5f(x) = 3(x - 2)^2 + 5. In the xyxy-plane, the graph of y=f(x)y = f(x) intersects the yy-axis at the point (0,c)(0, c). What is the value of cc?

Cevabı ve açıklamayı göster

Cevap: 17

Cevap

The correct answer is 17.
To find the yy-intercept of the graph of y=f(x)y = f(x), we substitute x=0x = 0 into the equation: f(0)=3(02)2+5f(0) = 3(0 - 2)^2 + 5. Simplifying the expression inside the parentheses gives 3(2)2+53(-2)^2 + 5. Squaring 2-2 gives 44, making the expression 3(4)+5=12+5=173(4) + 5 = 12 + 5 = 17. Therefore, the graph intersects the yy-axis at the point (0,17)(0, 17), which means the value of cc is 17.

Adım Adım Çözüm

1
Set x=0x = 0 to find the point where the graph intersects the yy-axis.
f(0)=3(02)2+5f(0) = 3(0 - 2)^2 + 5
The yy-intercept of any graph in the xyxy-plane occurs when the xx-coordinate is equal to 00.
2
Perform the arithmetic evaluation to find the value of f(0)f(0).
f(0)=17f(0) = 17
First, evaluate the term inside the parentheses: 02=20 - 2 = -2. Squaring 2-2 gives 44. Then, multiply 33 by 44 to get 1212. Finally, add 55 to obtain 1717.

Anahtar Kavram

Evaluating a quadratic function at x=0x = 0 to determine its yy-intercept.
Soru 1579Soru

In the quadratic equation x2+bx+c=0x^2 + bx + c = 0, bb and cc are integers such that b+c=10b + c = 10. If the equation has no real solutions, what is the maximum possible value of cc?

Cevabı ve açıklamayı göster

Cevap: 18

Cevap

The maximum possible value of cc is 18.
For the quadratic equation to have no real solutions, the discriminant b24acb^2 - 4ac must be negative. Given a=1a=1, this simplifies to b24c<0b^2 - 4c < 0. Using the constraint b+c=10b + c = 10, we can express cc as 10b10 - b. Substituting this into the inequality gives b24(10b)<0b^2 - 4(10 - b) < 0, which simplifies to b2+4b40<0b^2 + 4b - 40 < 0. Solving the boundary equation b2+4b40=0b^2 + 4b - 40 = 0 using the quadratic formula gives b=2±44b = -2 \pm \sqrt{44}. Since 446.63\sqrt{44} \approx 6.63, the boundary values of bb are approximately 8.63-8.63 and 4.634.63. Thus, the inequality holds for 8.63<b<4.63-8.63 < b < 4.63. To maximize c=10bc = 10 - b, we need the smallest integer value for bb in this range, which is b=8b = -8. Substituting b=8b = -8 gives the maximum value of c=10(8)=18c = 10 - (-8) = 18.

Adım Adım Çözüm

1
State the condition for the quadratic equation to have no real solutions.
The discriminant must be negative: b24ac<0b^2 - 4ac < 0. Since a=1a = 1, this simplifies to b24c<0b^2 - 4c < 0.
A quadratic equation has no real solutions if and only if its discriminant is strictly less than zero.
2
Express cc in terms of bb using the given equation b+c=10b + c = 10, and substitute it into the discriminant inequality.
Since c=10bc = 10 - b, substituting gives b24(10b)<0b^2 - 4(10 - b) < 0, which simplifies to b2+4b40<0b^2 + 4b - 40 < 0.
Substituting one variable in terms of the other allows us to solve a single-variable quadratic inequality.
3
Find the boundary values of bb by solving the equation b2+4b40=0b^2 + 4b - 40 = 0 using the quadratic formula.
b=4±424(1)(40)2=4±1762=2±44b = \frac{-4 \pm \sqrt{4^2 - 4(1)(-40)}}{2} = \frac{-4 \pm \sqrt{176}}{2} = -2 \pm \sqrt{44}. Since 446.63\sqrt{44} \approx 6.63, the boundaries are approximately b8.63b \approx -8.63 and b4.63b \approx 4.63.
The roots of the quadratic equation define the boundaries of the interval that satisfies the inequality.
4
Determine the interval for bb that satisfies the inequality and identify the value of bb that maximizes cc.
The inequality b2+4b40<0b^2 + 4b - 40 < 0 is satisfied when 8.63<b<4.63-8.63 < b < 4.63. Since c=10bc = 10 - b, maximizing cc requires selecting the smallest possible integer value of bb in this range, which is b=8b = -8.
Subtracting a smaller number from 10 results in a larger value for cc.
5
Calculate the maximum value of cc using the optimal value of bb.
c=10(8)=18c = 10 - (-8) = 18.
Substituting the minimum integer value of bb gives the maximum integer value of cc.

Anahtar Kavram

Analyzing the discriminant of a quadratic equation to determine the nature of its roots and using substitution to solve optimization problems under constraints.
Soru 1580Soru

If zz is a positive number such that z24z12=0z^2 - 4z - 12 = 0, what is the value of zz?

Cevabı ve açıklamayı göster

Cevap: 6

Cevap

The correct answer is 6.
To find the positive value of zz that satisfies the equation z24z12=0z^2 - 4z - 12 = 0, we factor the quadratic expression. Finding two numbers that multiply to 12-12 and add to 4-4 gives 6-6 and 22. Thus, the equation can be factored as (z6)(z+2)=0(z - 6)(z + 2) = 0. Setting each factor to zero yields the solutions z=6z = 6 and z=2z = -2. Since the problem states that zz is a positive number, we discard the negative solution, leaving 66 as the final answer.

Adım Adım Çözüm

1
Factor the quadratic equation z24z12=0z^2 - 4z - 12 = 0.
(z6)(z+2)=0(z - 6)(z + 2) = 0
To solve the quadratic equation by finding two numbers that multiply to -12 and add to -4.
2
Solve for the roots of the equation.
z=6z = 6 or z=2z = -2
Set each factor equal to zero and solve for zz.
3
Apply the constraint that zz must be positive.
z=6z = 6
Discard the negative solution z=2z = -2 as the problem specifies zz must be a positive number.

Anahtar Kavram

Solving quadratic equations by factoring
ÖncekiSayfa 79 / 140Sonraki
Tüm alıştırma soruları — SAT | Examkin