Algebra

432 soru

Soru 1Soru

A florist sells carnations for 1.501.50 each and roses for 3.003.00 each. The equation 1.50c+3.00r=45.001.50c + 3.00r = 45.00 represents the possible number of carnations, cc, and roses, rr, that a customer can buy for exactly 45.0045.00. If the customer buys 8 carnations, how many roses can they buy?

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Cevap: 11

Cevap

11
To find the number of roses the customer can buy, substitute the number of carnations bought, which is 8, for cc in the given equation. This yields 1.50(8)+3.00r=45.001.50(8) + 3.00r = 45.00. Simplifying the product gives 12.00+3.00r=45.0012.00 + 3.00r = 45.00. Subtracting 12.00 from both sides of the equation gives 3.00r=33.003.00r = 33.00. Finally, dividing both sides by 3.00 yields r=11r = 11. Thus, the customer can buy 11 roses.

Adım Adım Çözüm

1
Substitute the given value for carnations, c=8c = 8, into the linear equation.
1.50(8)+3.00r=45.001.50(8) + 3.00r = 45.00
We are given that the customer buys 8 carnations, so cc is replaced by 8 to solve for the number of roses, rr.
2
Multiply 1.501.50 by 88 to simplify the term.
12.00+3.00r=45.0012.00 + 3.00r = 45.00
Simplifying the constant term on the left side of the equation.
3
Subtract 12.0012.00 from both sides of the equation to isolate the term with rr.
3.00r=33.003.00r = 33.00
To solve for rr, we must get the term 3.00r3.00r by itself on one side.
4
Divide both sides of the equation by 3.003.00 to solve for rr.
r=11r = 11
Dividing isolates the variable rr.

Anahtar Kavram

Solving a linear equation in two variables by substitution when one variable's value is known.
Soru 2Soru

In the equation below, aa is a constant.

13(ax2)12(x4a)=3x5 \frac{1}{3}(ax - 2) - \frac{1}{2}(x - 4a) = 3x - 5

If the solution to the equation is x=2x = 2, what is the value of aa?

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Cevap: 11

Cevap

1
Substituting x=2x = 2 into the equation gives 13(2a2)12(24a)=3(2)5\frac{1}{3}(2a - 2) - \frac{1}{2}(2 - 4a) = 3(2) - 5, which simplifies to 13(2a2)(12a)=1\frac{1}{3}(2a - 2) - (1 - 2a) = 1. Multiplying the entire equation by 3 to clear the fraction yields (2a2)3(12a)=3(2a - 2) - 3(1 - 2a) = 3. Distributing the negative 3 yields 2a23+6a=32a - 2 - 3 + 6a = 3, which simplifies to 8a5=38a - 5 = 3. Adding 5 to both sides results in 8a=88a = 8, which gives a=1a = 1.

Adım Adım Çözüm

1
Substitute x=2x = 2 into the given equation.
13(2a2)12(24a)=3(2)5\frac{1}{3}(2a - 2) - \frac{1}{2}(2 - 4a) = 3(2) - 5
Since x=2x = 2 is a solution to the equation, substituting it into the equation must yield a true mathematical statement.
2
Simplify the constant terms and distribute or simplify the expressions.
13(2a2)(12a)=1\frac{1}{3}(2a - 2) - (1 - 2a) = 1
Simplifying 3(2)53(2) - 5 yields 11, and simplifying the second fraction term gives 12(24a)=12a\frac{1}{2}(2 - 4a) = 1 - 2a.
3
Multiply the entire equation by 3 to eliminate the fraction.
(2a2)3(12a)=3(2a - 2) - 3(1 - 2a) = 3
Multiplying all terms on both sides of the equation by the denominator 3 clears the fraction and simplifies the equation.
4
Distribute the negative 3 and combine like terms to solve for aa.
2a23+6a=3    8a5=3    8a=8    a=12a - 2 - 3 + 6a = 3 \implies 8a - 5 = 3 \implies 8a = 8 \implies a = 1
Distributing 3(12a)-3(1 - 2a) yields 3+6a-3 + 6a. Combining like terms gives 8a5=38a - 5 = 3, and adding 5 followed by dividing by 8 isolates the variable aa.

Anahtar Kavram

Solving linear equations in one variable containing fractions and constant parameters by substitution and term isolation.
Tahmini Süre:2m 0s
Soru 3Soru

If 52(x+3)=95 - 2(x + 3) = -9, what is the value of xx?

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Cevap: 4

Cevap

4
Distributing the 2-2 to both terms in the parentheses gives the equation 52x6=95 - 2x - 6 = -9. Combining the constants on the left side yields 2x1=9-2x - 1 = -9. Adding 11 to both sides gives 2x=8-2x = -8. Finally, dividing by 2-2 yields the correct value of 44.

Adım Adım Çözüm

1
Distribute the 2-2 to both terms inside the parentheses: 2-2 times xx and 2-2 times 33.
52x6=95 - 2x - 6 = -9
To remove the parentheses and simplify the equation.
2
Combine the constant terms on the left side of the equation: 565 - 6.
2x1=9-2x - 1 = -9
To group like terms together before isolating the variable.
3
Add 11 to both sides of the equation.
2x=8-2x = -8
To isolate the variable term on the left side of the equation.
4
Divide both sides of the equation by 2-2.
x=4x = 4
To solve for xx.

Anahtar Kavram

Solving a linear equation in one variable by distributing, combining like terms, and isolating the variable.
Soru 4Soru

Two lines, L1L_1 and L2L_2, are graphed in the xyxy-plane. Line L1L_1 passes through the points (2,11)(2, 11) and (6,23)(6, 23). If line L2L_2 is perpendicular to line L1L_1 and contains the point (3,10)(3, 10), what is the xx-coordinate of the xx-intercept of line L2L_2?

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Cevap: 33

Cevap

33
To find the xx-coordinate of the xx-intercept of line L2L_2, first determine the slope of line L1L_1 from the given points (2,11)(2, 11) and (6,23)(6, 23) using the formula m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1}, which results in m1=231162=3m_1 = \frac{23 - 11}{6 - 2} = 3. Since line L2L_2 is perpendicular to line L1L_1, its slope must be the negative reciprocal of 3, which is 13-\frac{1}{3}. Using the point-slope form with the point (3,10)(3, 10), the equation of line L2L_2 is y10=13(x3)y - 10 = -\frac{1}{3}(x - 3), which simplifies to y=13x+11y = -\frac{1}{3}x + 11. Setting y=0y = 0 to find the xx-intercept yields 0=13x+110 = -\frac{1}{3}x + 11, which simplifies to x=33x = 33.

Adım Adım Çözüm

1
Calculate the slope of line L1L_1 using the points (2,11)(2, 11) and (6,23)(6, 23) with the slope formula m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1}.
m1=231162=124=3m_1 = \frac{23 - 11}{6 - 2} = \frac{12}{4} = 3
The slope of a line represents its rate of change and is required to find the relationship with perpendicular lines.
2
Find the slope of line L2L_2 which is perpendicular to L1L_1.
m2=13m_2 = -\frac{1}{3}
Perpendicular lines have slopes that are negative reciprocals of each other.
3
Write the linear equation for line L2L_2 using the point-slope formula yy1=m(xx1)y - y_1 = m(x - x_1) with the point (3,10)(3, 10) and slope m2=13m_2 = -\frac{1}{3}.
y10=13(x3)    y=13x+11y - 10 = -\frac{1}{3}(x - 3) \implies y = -\frac{1}{3}x + 11
Defining the equation of the line allows us to find the coordinates of any of its intercepts.
4
Set y=0y = 0 in the equation for line L2L_2 to find the xx-coordinate of the xx-intercept.
0=13x+11    13x=11    x=330 = -\frac{1}{3}x + 11 \implies \frac{1}{3}x = 11 \implies x = 33
The xx-intercept is the point where the line crosses the xx-axis, which mathematically corresponds to y=0y = 0.

Anahtar Kavram

Perpendicular lines in the coordinate plane have slopes that are negative reciprocals of each other. The xx-intercept of a linear graph represents the value of xx when y=0y = 0.
Soru 5Soru

Consider the system of linear equations below.

3x4y=72x+3y=16\begin{aligned} 3x - 4y &= 7 \\ 2x + 3y &= 16 \end{aligned}

If (x,y)(x, y) is the solution to the system of equations above, what is the value of x+yx + y?

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Cevap: 7

Cevap

7
The correct answer is 7. By multiplying the first equation by 3 and the second by 4, we get 9x12y=219x - 12y = 21 and 8x+12y=648x + 12y = 64. Adding these equations eliminates the yy terms and gives 17x=8517x = 85, which simplifies to x=5x = 5. Substituting x=5x = 5 into the second equation yields 2(5)+3y=16    10+3y=16    3y=6    y=22(5) + 3y = 16 \implies 10 + 3y = 16 \implies 3y = 6 \implies y = 2. The sum of the coordinates is x+y=5+2=7x + y = 5 + 2 = 7.

Adım Adım Çözüm

1
Multiply the equations by constants to align the coefficients of one variable for elimination.
Multiplying the first equation by 3 gives 9x12y=219x - 12y = 21. Multiplying the second equation by 4 gives 8x+12y=648x + 12y = 64.
This sets up the system so that the yy terms have opposite coefficients (12-12 and +12+12), allowing them to be eliminated by addition.
2
Add the two modified equations to eliminate the yy variable and solve for xx.
(9x12y)+(8x+12y)=21+64    17x=85    x=5(9x - 12y) + (8x + 12y) = 21 + 64 \implies 17x = 85 \implies x = 5.
Adding the equations eliminates yy and leaves a single linear equation in terms of xx.
3
Substitute the value of xx back into one of the original equations to solve for yy.
Substituting x=5x = 5 into the second equation 2x+3y=162x + 3y = 16 gives 2(5)+3y=16    10+3y=16    3y=6    y=22(5) + 3y = 16 \implies 10 + 3y = 16 \implies 3y = 6 \implies y = 2.
Plugging the known variable value back in allows us to solve for the remaining unknown variable.
4
Calculate the value of the requested expression x+yx + y.
x+y=5+2=7x + y = 5 + 2 = 7.
The question specifically asks for the sum of xx and yy.

Anahtar Kavram

Solving systems of linear equations using the elimination method and evaluating linear combinations of the solutions.

Alternatif Yöntem

Alternatively, you can solve the first equation for xx in terms of yy: 3x=7+4y    x=7+4y33x = 7 + 4y \implies x = \frac{7+4y}{3}. Substitute this expression into the second equation: 2(7+4y3)+3y=162\left(\frac{7+4y}{3}\right) + 3y = 16. Multiply the entire equation by 3 to clear the fraction: 2(7+4y)+9y=48    14+8y+9y=48    17y=34    y=22(7+4y) + 9y = 48 \implies 14 + 8y + 9y = 48 \implies 17y = 34 \implies y = 2. Substitute y=2y = 2 back to find xx: x=7+4(2)3=5x = \frac{7+4(2)}{3} = 5. Thus, x+y=5+2=7x + y = 5 + 2 = 7.
Tahmini Süre:1m 30s
Soru 6Soru

A digital marketing firm allocates its monthly advertising budget between search engine campaigns and social media campaigns. Let xx represent the amount, in thousands of dollars, spent on search engine campaigns, and let yy represent the amount, in thousands of dollars, spent on social media campaigns. The system of inequalities below represents the firm's monthly constraints:

x2yx+y253x+4y80y3\begin{aligned} x &\ge 2y \\ x + y &\le 25 \\ 3x + 4y &\le 80 \\ y &\ge 3 \end{aligned}

Based on these constraints, what is the maximum possible amount, in thousands of dollars, the firm can spend on social media campaigns?

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Cevap: 8

Cevap

8
To find the maximum possible value of yy, we analyze the boundaries of the feasible region. The boundary lines of the system are x=2yx = 2y, x+y=25x + y = 25, 3x+4y=803x + 4y = 80, and y=3y = 3. We can find the upper limit of yy by combining the inequalities x2yx \ge 2y and 3x+4y803x + 4y \le 80. Multiplying the first inequality by 33 gives 3x6y3x \ge 6y. Adding 4y4y to both sides yields 3x+4y10y3x + 4y \ge 10y. Because 3x+4y803x + 4y \le 80, it follows that 10y8010y \le 80, which simplifies to y8y \le 8. We verify that the point (16,8)(16, 8) satisfies the remaining inequalities: 16+8=242516 + 8 = 24 \le 25 and 838 \ge 3, which are both true. Thus, the maximum possible value of yy is 88.

Adım Adım Çözüm

1
Relate the variables using the constraints to establish an upper bound for yy.
Since x2yx \ge 2y, multiplying both sides by 33 gives 3x6y3x \ge 6y.
This allows us to express the 3x3x term in the cost inequality in terms of yy to determine the maximum boundary.
2
Substitute 3x6y3x \ge 6y into the inequality 3x+4y803x + 4y \le 80.
We get 6y+4y3x+4y806y + 4y \le 3x + 4y \le 80, which simplifies to 10y8010y \le 80.
This establishes a direct upper limit for yy based on the intersection of the two active boundary lines.
3
Solve the inequality 10y8010y \le 80 for yy.
y8y \le 8.
This determines that the maximum possible value for yy under these constraints is 88.
4
Verify that the point corresponding to y=8y = 8 satisfies all other constraints in the system.
When y=8y = 8, the boundary x=2yx = 2y gives x=16x = 16. Checking (16,8)(16, 8) against all inequalities:
- 162(8)    161616 \ge 2(8) \implies 16 \ge 16 (True)
- 16+825    242516 + 8 \le 25 \implies 24 \le 25 (True)
- 3(16)+4(8)80    80803(16) + 4(8) \le 80 \implies 80 \le 80 (True)
- 838 \ge 3 (True)
We must verify that the optimal vertex lies within the feasible region defined by all four inequalities.

Anahtar Kavram

Maximizing a coordinate value within a bounded feasible region defined by a system of linear inequalities.
Soru 7Soru

A landscaping company uses the equation 12x+18y=24012x + 18y = 240 to model the total cost, in dollars, of renting a wood chipper for xx hours and a soil aerator for yy hours. If the wood chipper was rented for 5 more hours than the soil aerator, and the company spent a total of 240240 on these rentals, for how many hours was the soil aerator rented?

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Cevap: 6

Cevap

The soil aerator was rented for 6 hours.
The correct answer is 6. By writing the relationship between the rental hours as x=y+5x = y + 5 and substituting this expression into the cost equation, we obtain 12(y+5)+18y=24012(y + 5) + 18y = 240. Distributing the 12 results in 12y+60+18y=24012y + 60 + 18y = 240. Combining the like terms gives 30y+60=24030y + 60 = 240. Subtracting 60 from both sides of the equation yields 30y=18030y = 180. Dividing both sides by 30 results in y=6y = 6. Therefore, the soil aerator was rented for 6 hours.

Adım Adım Çözüm

1
Express the relationship between the rental hours of the wood chipper (xx) and the soil aerator (yy) as an equation.
x=y+5x = y + 5
The wood chipper was rented for 5 more hours than the soil aerator.
2
Substitute the expression for xx into the cost equation 12x+18y=24012x + 18y = 240.
12(y+5)+18y=24012(y + 5) + 18y = 240
Substitution reduces the equation to a single variable, allowing us to solve for yy.
3
Distribute the 12 and combine like terms.
12y+60+18y=240    30y+60=24012y + 60 + 18y = 240 \implies 30y + 60 = 240
Simplification isolates the variable terms on one side.
4
Isolate yy by subtracting 60 from both sides and then dividing by 30.
30y=180    y=630y = 180 \implies y = 6
This calculation yields the rental hours for the soil aerator.

Anahtar Kavram

Solving a system of linear equations in two variables where one equation represents a budget constraint and the other relates the quantities of the two variables.
Soru 8Soru

A commercial agricultural irrigation system distributes liquid fertilizer from a storage tank. The volume of fertilizer remaining in the tank, VV, in liters, mm minutes after the system is turned on is modeled by the equation:

V=1,80015(m3c)V = 1,800 - 15(m - 3c)

where cc is the number of times the system's nozzles are cleaned during the irrigation process. During each cleaning cycle, the flow of fertilizer is completely paused, and no fertilizer is distributed. Based on the model, what is the duration, in minutes, of a single cleaning cycle?

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Cevap: 3

Cevap

The duration of a single cleaning cycle is 3 minutes.
In the model V=1,80015(m3c)V = 1,800 - 15(m - 3c), the term (m3c)(m - 3c) represents the total time, in minutes, that the irrigation system is actively distributing fertilizer. Since the total elapsed time is mm minutes and the system pauses during cleaning cycles, the term 3c3c represents the total paused time for cc cleanings. Therefore, the duration of a single cleaning cycle is 3cc=3\frac{3c}{c} = 3 minutes.

Adım Adım Çözüm

1
Analyze the structure of the equation to identify the meaning of each term.
The coefficient 15 is the active flow rate in liters per minute, and (m3c)(m - 3c) is the active distribution time in minutes.
To understand how the time variables affect the volume of fertilizer remaining.
2
Relate the total elapsed time to the active time and the paused time.
The total elapsed time is mm minutes, and the active time is m3cm - 3c minutes, meaning the system is paused for a total of 3c3c minutes.
To find the expression for the total duration of all cleaning cycles.
3
Determine the duration of a single cleaning cycle.
Since cc cleaning cycles result in a total pause of 3c3c minutes, each cycle lasts 3cc=3\frac{3c}{c} = 3 minutes.
To calculate the duration of one individual cleaning cycle.

Anahtar Kavram

Interpreting Linear Relationships in Context
Soru 9Soru

In the system of equations below, what is the value of yy?

4x+3y=254x + 3y = 25
2x+3y=172x + 3y = 17
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Cevap: 3

Cevap

The value of yy is 33.
Subtracting the second equation from the first equation gives (4x+3y)(2x+3y)=2517(4x + 3y) - (2x + 3y) = 25 - 17, which simplifies to 2x=82x = 8. Dividing by 2 gives x=4x = 4. Substituting x=4x = 4 into the second equation gives 2(4)+3y=172(4) + 3y = 17, which simplifies to 8+3y=178 + 3y = 17. Subtracting 8 from both sides gives 3y=93y = 9, and dividing by 3 gives y=3y = 3.

Adım Adım Çözüm

1
Subtract the second equation from the first equation to eliminate the yy term.
2x=82x = 8
Subtracting the equations eliminates 3y3y since it is common to both equations, leaving a single variable equation.
2
Solve for xx by dividing both sides of the equation by 2.
x=4x = 4
Dividing isolates the variable xx so we can find its numerical value.
3
Substitute x=4x = 4 into the second equation 2x+3y=172x + 3y = 17 and solve for yy.
y=3y = 3
Substituting the value of xx leaves only the variable yy, which can then be isolated and solved.

Anahtar Kavram

Solving systems of linear equations using elimination
Soru 10Soru

Two linear equations are defined as follows:

3x+2y=123x + 2y = 12
x2y=4x - 2y = 4

If the ordered pair (x,y)(x, y) satisfies both equations, what is the value of xx?

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Cevap: 4

Cevap

The value of xx is 4.
Adding the two equations 3x+2y=123x + 2y = 12 and x2y=4x - 2y = 4 eliminates the yy terms, resulting in 4x=164x = 16. Dividing both sides by 4 gives the value of xx as 4.

Adım Adım Çözüm

1
Add the two equations together to eliminate the yy variable.
4x=164x = 16
Since the coefficients of yy are opposites (22 and 2-2), adding the equations eliminates yy directly.
2
Divide both sides of the equation by 4.
x=4x = 4
To isolate the variable xx.

Anahtar Kavram

Solving systems of linear equations using the elimination method.

Alternatif Yöntem

We can solve the second equation for xx to get x=2y+4x = 2y + 4. Substituting this expression into the first equation gives 3(2y+4)+2y=123(2y + 4) + 2y = 12, which simplifies to 6y+12+2y=126y + 12 + 2y = 12, or 8y=08y = 0, meaning y=0y = 0. Substituting y=0y = 0 back into x=2y+4x = 2y + 4 yields x=4x = 4.
Tahmini Süre:45s
Soru 11Soru

If 23(3x12)34(2x13)=16(x+4)512\frac{2}{3}\left(3x - \frac{1}{2}\right) - \frac{3}{4}\left(2x - \frac{1}{3}\right) = \frac{1}{6}(x + 4) - \frac{5}{12}, what is the value of 12x512x - 5?

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Cevap: 7

Cevap

7
The correct answer is 7. Expanding the left side of the equation yields 2x1332x+14=12x1122x - \frac{1}{3} - \frac{3}{2}x + \frac{1}{4} = \frac{1}{2}x - \frac{1}{12}. Expanding the right side yields 16x+46512=16x+14\frac{1}{6}x + \frac{4}{6} - \frac{5}{12} = \frac{1}{6}x + \frac{1}{4}. Setting the two sides equal gives 12x112=16x+14\frac{1}{2}x - \frac{1}{12} = \frac{1}{6}x + \frac{1}{4}. Multiplying all terms by 12 clears the fractions, resulting in 6x1=2x+36x - 1 = 2x + 3. Solving for xx gives 4x=44x = 4, which means x=1x = 1. Substituting x=1x = 1 into 12x512x - 5 yields 12(1)5=712(1) - 5 = 7.

Adım Adım Çözüm

1
Distribute the factors on the left side of the equation: 23(3x12)\frac{2}{3}\left(3x - \frac{1}{2}\right) and 34(2x13)-\frac{3}{4}\left(2x - \frac{1}{3}\right).
2x1332x+142x - \frac{1}{3} - \frac{3}{2}x + \frac{1}{4}
To eliminate the parentheses and prepare the left side of the equation for combining like terms.
2
Combine the variable terms and the constant terms on the left side: (2x32x)+(13+14)\left(2x - \frac{3}{2}x\right) + \left(-\frac{1}{3} + \frac{1}{4}\right).
12x112\frac{1}{2}x - \frac{1}{12}
To simplify the left side into a single linear expression with a common denominator for the constants.
3
Expand and simplify the right side of the equation: 16(x+4)512\frac{1}{6}(x + 4) - \frac{5}{12}.
16x+14\frac{1}{6}x + \frac{1}{4}
By distributing 16\frac{1}{6}, we get 16x+46512\frac{1}{6}x + \frac{4}{6} - \frac{5}{12}. Finding a common denominator of 12 for the constant terms yields 812512=312=14\frac{8}{12} - \frac{5}{12} = \frac{3}{12} = \frac{1}{4}.
4
Equate the simplified left and right sides: 12x112=16x+14\frac{1}{2}x - \frac{1}{12} = \frac{1}{6}x + \frac{1}{4}. Multiply both sides of the equation by 12 to clear the fractions.
6x1=2x+36x - 1 = 2x + 3, which simplifies to 4x=44x = 4, and thus x=1x = 1.
To solve for the variable xx in a simplified integer form.
5
Substitute x=1x = 1 into the requested expression 12x512x - 5.
12(1)5=712(1) - 5 = 7
To calculate the final value asked by the question.

Anahtar Kavram

Solving multi-step linear equations in one variable with fractional coefficients, distributing negative signs, and evaluating expressions.
Soru 12Soru

The graph of the linear equation y=3x7y = 3x - 7 contains the point (k,5)(k, 5). What is the value of kk?

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Cevap: 44

Cevap

The value of kk is 44.
Substituting the coordinates of the point (k,5)(k, 5) into the linear equation y=3x7y = 3x - 7 gives 5=3k75 = 3k - 7. Solving for kk involves adding 77 to both sides of the equation to get 12=3k12 = 3k, and then dividing both sides by 33 to find k=4k = 4.

Adım Adım Çözüm

1
Substitute the point (k,5)(k, 5) into the equation of the line y=3x7y = 3x - 7 by setting x=kx = k and y=5y = 5.
5=3k75 = 3k - 7
Since the point lies on the graph of the equation, its coordinates must satisfy the equation.
2
Isolate the term with kk by adding 77 to both sides of the equation.
12=3k12 = 3k
Adding 77 to both sides cancels the 7-7 on the right side.
3
Solve for kk by dividing both sides of the equation by 33.
k=4k = 4
Dividing by 33 isolates kk.

Anahtar Kavram

Determining an unknown coordinate of a point on a line by substituting the point's coordinates into the linear equation in two variables.
Soru 13Soru

Let pp and qq be constants. The inequality p(x5)<q(x+4)p(x - 5) < q(x + 4) has the solution set x>2x > 2. If pq=3p - q = -3, what is the value of p+qp + q?

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Cevap: -1

Cevap

-1
The correct answer is 1-1. Expanding the inequality p(x5)<q(x+4)p(x - 5) < q(x + 4) gives px5p<qx+4qpx - 5p < qx + 4q. Grouping the xx terms yields (pq)x<5p+4q(p - q)x < 5p + 4q. Since pq=3p - q = -3, which is negative, dividing both sides by pqp - q reverses the inequality to x>5p+4qpqx > \frac{5p + 4q}{p - q}. Comparing this to the given solution x>2x > 2, the boundary value must satisfy 5p+4q3=2\frac{5p + 4q}{-3} = 2, which simplifies to 5p+4q=65p + 4q = -6. Using the system of equations pq=3p - q = -3 and 5p+4q=65p + 4q = -6, we find p=2p = -2 and q=1q = 1. Therefore, the value of p+qp + q is 2+1=1-2 + 1 = -1.

Adım Adım Çözüm

1
Expand both sides of the inequality and group the terms with xx on one side.
(pq)x<5p+4q(p - q)x < 5p + 4q
Expanding p(x5)<q(x+4)p(x - 5) < q(x + 4) gives px5p<qx+4qpx - 5p < qx + 4q. Subtracting qxqx and adding 5p5p to both sides yields pxqx<5p+4qpx - qx < 5p + 4q, which factors to (pq)x<5p+4q(p - q)x < 5p + 4q.
2
Determine the direction of the inequality when isolating xx.
x>5p+4qpqx > \frac{5p + 4q}{p - q}
Since we are given pq=3p - q = -3, the quantity pqp - q is negative. Dividing both sides of the inequality by a negative value reverses the inequality symbol from << to >>.
3
Equate the resulting boundary expression to the boundary of the given solution set x>2x > 2.
5p + 4q = -6
The boundary value of the solution set is 22, so we set 5p+4qpq=2\frac{5p + 4q}{p - q} = 2. Substituting pq=3p - q = -3 gives 5p+4q3=2\frac{5p + 4q}{-3} = 2, which simplifies to 5p+4q=65p + 4q = -6.
4
Solve the system of linear equations for pp and qq.
p=2p = -2 and q=1q = 1
We have the system of equations pq=3p - q = -3 and 5p+4q=65p + 4q = -6. From the first equation, p=q3p = q - 3. Substituting this into the second equation gives 5(q3)+4q=6    9q15=6    9q=9    q=15(q - 3) + 4q = -6 \implies 9q - 15 = -6 \implies 9q = 9 \implies q = 1. Substituting q=1q = 1 back into p=q3p = q - 3 gives p=2p = -2.
5
Calculate the value of p+qp + q.
-1
Adding the values of pp and qq gives p+q=2+1=1p + q = -2 + 1 = -1.

Anahtar Kavram

Solving linear inequalities in one variable with variable coefficients and applying sign reversal rules.
Soru 14Soru

A community garden charges a one-time registration fee plus a monthly fee to plot and maintain a garden bed. The total cost, yy, in dollars, of maintaining a garden bed for xx months is given by the equation y=15x+45y = 15x + 45. If a gardener spent a total of 165165 dollars, for how many months did they maintain the garden bed?

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Cevap: 8

Cevap

The correct answer is 8. Setting the total cost y equal to 165 in the linear equation yields 165 = 15x + 45. Subtracting 45 from both sides gives 120 = 15x, and dividing by 15 results in x = 8 months.
To find the number of months the gardener maintained the garden bed, substitute the total spent, 165165, for yy in the equation y=15x+45y = 15x + 45. This results in 165=15x+45165 = 15x + 45. Subtracting 4545 from both sides of the equation yields 120=15x120 = 15x. Dividing both sides by 1515 gives x=8x = 8. Thus, the garden bed was maintained for 8 months.

Adım Adım Çözüm

1
Substitute 165 for y in the equation.
165=15x+45165 = 15x + 45
The variable y represents the total cost in dollars, which is given as 165.
2
Subtract 45 from both sides of the equation.
120=15x120 = 15x
This isolates the variable term by subtracting the constant registration fee.
3
Divide both sides of the equation by 15.
x=8x = 8
This solves for x, the number of months.

Anahtar Kavram

Solving for a variable in a linear equation representing a real-world scenario.
Soru 15Soru

An online bookstore charges a flat shipping fee plus a fixed price per book purchased. The total cost, yy, in dollars, for purchasing xx books is given by the equation y=8.5x+4.5y = 8.5x + 4.5. If a customer's total cost was 4747 dollars, how many books did the customer purchase?

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Cevap: 5

Cevap

The customer purchased 5 books.
To find the number of books purchased, substitute the total cost of 47 for yy in the equation y=8.5x+4.5y = 8.5x + 4.5, yielding 47=8.5x+4.547 = 8.5x + 4.5. Subtracting 4.54.5 from both sides gives 42.5=8.5x42.5 = 8.5x. Dividing both sides by 8.58.5 results in x=5x = 5. Thus, the customer purchased 5 books.

Adım Adım Çözüm

1
Substitute the total cost of 47 into the equation for y
47=8.5x+4.547 = 8.5x + 4.5
Since the total cost is represented by y and is given as 47 dollars, we substitute 47 for y in the equation.
2
Subtract 4.5 from both sides of the equation
42.5=8.5x42.5 = 8.5x
Subtracting the flat fee from both sides isolates the variable term representing the total cost of the books.
3
Divide both sides by 8.5
x=5x = 5
Dividing the remaining cost by the price per book yields the total number of books purchased.

Anahtar Kavram

Linear Equations in Two Variables
Soru 16Soru

If 12(4x8)23(39x)=5(x1)+7\frac{1}{2}(4x - 8) - \frac{2}{3}(3 - 9x) = 5(x - 1) + 7, what is the value of 3x23x - 2?

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Cevap: 6

Cevap

6
The correct value is 6. After correctly distributing the coefficients on both sides, the equation becomes 8x6=5x+28x - 6 = 5x + 2. Isolating the variable yields 3x=83x = 8, which gives x=83x = \frac{8}{3}. Substituting this back into the target expression 3x23x - 2 results in 3(83)2=63(\frac{8}{3}) - 2 = 6.

Adım Adım Çözüm

1
Distribute the fraction coefficients on the left side of the equation.
12(4x8)23(39x)=2x42+6x=8x6\frac{1}{2}(4x - 8) - \frac{2}{3}(3 - 9x) = 2x - 4 - 2 + 6x = 8x - 6
To simplify the expression by removing the parentheses on the left side.
2
Distribute and simplify the right side of the equation.
5(x1)+7=5x5+7=5x+25(x - 1) + 7 = 5x - 5 + 7 = 5x + 2
To simplify the expression by removing the parentheses on the right side.
3
Equate the simplified left and right sides, then solve for xx.
8x6=5x+2    3x=8    x=838x - 6 = 5x + 2 \implies 3x = 8 \implies x = \frac{8}{3}
To isolate the variable xx.
4
Substitute the value of xx into the expression 3x23x - 2.
3(83)2=82=63\left(\frac{8}{3}\right) - 2 = 8 - 2 = 6
To find the final value requested by the question.

Anahtar Kavram

Solving linear equations in one variable by distributing coefficients, combining like terms, and isolating the variable.
Tahmini Süre:2m 0s
Soru 17Soru
In the equation below, xx is a real number.
56(3x4)38(4x12)=14(2x+6)\frac{5}{6}(3x - 4) - \frac{3}{8}(4x - 12) = \frac{1}{4}(2x + 6)
What is the value of 6x56x - 5?
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Cevap: 1-1

Cevap

1-1
The correct answer is 1-1. First, distribute the fractions across the parentheses on both sides of the equation:
56(3x4)38(4x12)=14(2x+6)\frac{5}{6}(3x - 4) - \frac{3}{8}(4x - 12) = \frac{1}{4}(2x + 6)
52x10332x+92=12x+32\frac{5}{2}x - \frac{10}{3} - \frac{3}{2}x + \frac{9}{2} = \frac{1}{2}x + \frac{3}{2}
Combine the like terms on the left side:
(52x32x)+(103+92)=12x+32\left(\frac{5}{2}x - \frac{3}{2}x\right) + \left(-\frac{10}{3} + \frac{9}{2}\right) = \frac{1}{2}x + \frac{3}{2}
x+76=12x+32x + \frac{7}{6} = \frac{1}{2}x + \frac{3}{2}
Subtract 12x\frac{1}{2}x from both sides:
12x+76=32\frac{1}{2}x + \frac{7}{6} = \frac{3}{2}
Subtract 76\frac{7}{6} from both sides:
12x=9676=26=13\frac{1}{2}x = \frac{9}{6} - \frac{7}{6} = \frac{2}{6} = \frac{1}{3}
Multiply by 22 to solve for xx:
x=23x = \frac{2}{3}
Finally, substitute x=23x = \frac{2}{3} into the expression 6x56x - 5:
6(23)5=45=16\left(\frac{2}{3}\right) - 5 = 4 - 5 = -1

Adım Adım Çözüm

1
Distribute the coefficients to the terms within the parentheses on both sides of the equation.
52x10332x+92=12x+32\frac{5}{2}x - \frac{10}{3} - \frac{3}{2}x + \frac{9}{2} = \frac{1}{2}x + \frac{3}{2}
To simplify the linear equation, parenthetical expressions must be expanded.
2
Combine like terms on the left side of the equation.
x+76=12x+32x + \frac{7}{6} = \frac{1}{2}x + \frac{3}{2}
Grouping the variable terms (xx) and constant terms simplifies the equation prior to isolation.
3
Isolate the variable term on one side of the equation by subtracting 12x\frac{1}{2}x and 76\frac{7}{6} from both sides.
12x=13\frac{1}{2}x = \frac{1}{3}
This isolates the variable xx on the left side and the constants on the right side.
4
Solve for xx by multiplying both sides by 22.
x=23x = \frac{2}{3}
Multiplying by the reciprocal of the coefficient of xx gives the value of xx.
5
Substitute the value of xx into the expression 6x56x - 5.
1-1
The question asks for the value of the expression 6x56x - 5, not the variable xx.

Anahtar Kavram

Solving multi-step linear equations in one variable containing fractions and parentheses.
Soru 18Soru

If 5(x2)=3x+85(x - 2) = 3x + 8, what is the value of xx?

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Cevap: 9

Cevap

The value of xx is 9.
Distributing the 5 to both terms inside the parentheses yields 5x10=3x+85x - 10 = 3x + 8. Subtracting 3x3x from both sides gives 2x10=82x - 10 = 8. Adding 10 to both sides yields 2x=182x = 18. Dividing both sides by 2 gives the correct value of xx, which is 9.

Adım Adım Çözüm

1
Distribute the 5 to the terms inside the parentheses on the left side of the equation
5x10=3x+85x - 10 = 3x + 8
To simplify the left side of the equation by removing the parentheses.
2
Subtract 3x3x from both sides of the equation to collect the variable terms on one side
2x10=82x - 10 = 8
To isolate the variable term on the left side of the equation.
3
Add 10 to both sides of the equation to collect the constant terms on the other side
2x=182x = 18
To further isolate the variable term.
4
Divide both sides of the equation by 2
x=9x = 9
To solve for the variable xx.

Anahtar Kavram

Solving linear equations in one variable using distributive property and isolation of the variable.
Soru 19Soru

If xx is the solution to the equation 14(23x8)56(1235x)=13(x9)1\frac{1}{4}\left(\frac{2}{3}x - 8\right) - \frac{5}{6}\left(12 - \frac{3}{5}x\right) = \frac{1}{3}(x - 9) - 1, what is the value of 12x5\frac{1}{2}x - 5?

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Cevap: 7

Cevap

7
The correct answer is obtained by first distributing the fractions across the terms in the parentheses, which yields 16x210+12x=13x4\frac{1}{6}x - 2 - 10 + \frac{1}{2}x = \frac{1}{3}x - 4. Combining the like terms on the left side gives 23x12=13x4\frac{2}{3}x - 12 = \frac{1}{3}x - 4. Subtracting 13x\frac{1}{3}x from both sides and adding 1212 to both sides yields 13x=8\frac{1}{3}x = 8, which means x=24x = 24. Substituting 2424 for xx in the expression 12x5\frac{1}{2}x - 5 gives 12(24)5=125=7\frac{1}{2}(24) - 5 = 12 - 5 = 7.

Adım Adım Çözüm

1
Distribute the coefficients outside the parentheses on both sides of the equation.
16x210+12x=13x31\frac{1}{6}x - 2 - 10 + \frac{1}{2}x = \frac{1}{3}x - 3 - 1
To eliminate parentheses and simplify the terms.
2
Combine the like terms on the left and right sides of the equation.
23x12=13x4\frac{2}{3}x - 12 = \frac{1}{3}x - 4
To group the coefficients of xx and the constant values.
3
Isolate the variable xx by subtracting 13x\frac{1}{3}x and adding 1212 to both sides of the equation.
13x=8    x=24\frac{1}{3}x = 8 \implies x = 24
To solve for xx.
4
Substitute the value of xx into the expression 12x5\frac{1}{2}x - 5 to find the final value.
12(24)5=125=7\frac{1}{2}(24) - 5 = 12 - 5 = 7
To evaluate the requested expression.

Anahtar Kavram

Solving multi-step linear equations in one variable involving distribution, fractions, and grouping like terms.

Alternatif Yöntem

Instead of distributing fractions first, we can multiply the entire equation by the least common multiple of all denominators, which is 1212. This eliminates all fractions immediately: 3(23x8)10(1235x)=4(x9)123\left(\frac{2}{3}x - 8\right) - 10\left(12 - \frac{3}{5}x\right) = 4(x - 9) - 12. Expanding this gives 2x24120+6x=4x3612    8x144=4x48    4x=96    x=242x - 24 - 120 + 6x = 4x - 36 - 12 \implies 8x - 144 = 4x - 48 \implies 4x = 96 \implies x = 24. Substituting x=24x = 24 into the expression gives 77.
Tahmini Süre:3m 0s
Soru 20Soru

If 2(3x4)5(x1)=3(x+2)12(3x - 4) - 5(x - 1) = 3(x + 2) - 1, what is the value of 2x+32x + 3?

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Cevap: -5

Cevap

The correct answer is 5-5.
Solving the given equation step-by-step yields x=4x = -4. Substituting x=4x = -4 into the expression 2x+32x + 3 results in 2(4)+3=52(-4) + 3 = -5.

Adım Adım Çözüm

1
Distribute the values outside the parentheses on both sides of the equation.
6x85x+5=3x+616x - 8 - 5x + 5 = 3x + 6 - 1
This step removes parentheses so that like terms can be combined.
2
Combine like terms on each side of the equation.
x3=3x+5x - 3 = 3x + 5
Simplifying both sides makes it easier to isolate the variable.
3
Isolate the variable xx by subtracting xx and 55 from both sides.
x=4x = -4
This determines the value of xx which is required to evaluate the final expression.
4
Substitute the value of xx into the expression 2x+32x + 3.
2(4)+3=52(-4) + 3 = -5
This calculates the final value requested by the question.

Anahtar Kavram

Solving linear equations in one variable involving parentheses and distributing terms.
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Algebra Alıştırma Soruları — SAT | Examkin