Linear Inequalities and Absolute Value

52 soru

Soru 1Soru

If xx is a real number that satisfies the compound absolute value inequality 2x574||2x - 5| - 7| \le 4, which of the following values could be the value of xx? Select all such values.

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Cevap: 2-2; 00; 66

Cevap

The real numbers 2-2, 00, and 66 satisfy the inequality.
The solution set to the compound inequality 2x574||2x - 5| - 7| \le 4 is the union of two intervals: [3,1][-3, 1] and [4,8][4, 8]. Among the options provided, 2-2 and 00 fall into the interval [3,1][-3, 1], and 66 falls into the interval [4,8][4, 8]. Therefore, these three values satisfy the original inequality.

Adım Adım Çözüm

1
Unfold the outer absolute value inequality.
42x574-4 \le |2x - 5| - 7 \le 4
For any expression UU and constant c0c \ge 0, Uc|U| \le c is equivalent to cUc-c \le U \le c.
2
Isolate the inner absolute value term by adding 77 across all parts.
32x5113 \le |2x - 5| \le 11
Adding a constant preserves inequality directions.
3
Break the compound inequality into two separate absolute value conditions.
Condition 1: 2x511|2x - 5| \le 11; Condition 2: 2x53|2x - 5| \ge 3
Both conditions must hold simultaneously for xx.
4
Solve Condition 1 (2x511|2x - 5| \le 11).
112x511    62x16    3x8-11 \le 2x - 5 \le 11 \implies -6 \le 2x \le 16 \implies -3 \le x \le 8
Expanding the bounded absolute value inequality and solving for xx.
5
Solve Condition 2 (2x53|2x - 5| \ge 3).
2x532x - 5 \ge 3 or 2x53    2x82x - 5 \le -3 \implies 2x \ge 8 or 2x2    x42x \le 2 \implies x \ge 4 or x1x \le 1
For Uc|U| \ge c, UcU \ge c or UcU \le -c.
6
Find the intersection of the two solution sets.
x[3,1][4,8]x \in [-3, 1] \cup [4, 8]
Intersecting [3,8][-3, 8] with (,1][4,)(-\infty, 1] \cup [4, \infty) yields [3,1][4,8][-3, 1] \cup [4, 8].
7
Test the provided choices against the solution set [3,1][4,8][-3, 1] \cup [4, 8].
2[3,1]-2 \in [-3, 1] (valid), 0[3,1]0 \in [-3, 1] (valid), 3[3,1][4,8]3 \notin [-3, 1] \cup [4, 8] (invalid), 6[4,8]6 \in [4, 8] (valid), 9[3,1][4,8]9 \notin [-3, 1] \cup [4, 8] (invalid).
Values lying within the solution intervals satisfy the original inequality.

Anahtar Kavram

Solving nested absolute value inequalities using multi-step compound interval intersections.
Soru 2Soru

If xx is a real number that satisfies the inequality 52x7|5 - 2x| \le 7, what is the minimum possible value of the expression 34x3 - 4x?

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Cevap: 21-21

Cevap

21-21
Solving 52x7|5 - 2x| \le 7 yields 752x7-7 \le 5 - 2x \le 7. Subtracting 55 gives 122x2-12 \le -2x \le 2. Dividing by 2-2 and flipping the inequality direction gives 1x6-1 \le x \le 6. To minimize 34x3 - 4x, we choose the maximum value of xx because the term 4x-4x decreases as xx increases. Substituting x=6x = 6 yields 34(6)=213 - 4(6) = -21.

Adım Adım Çözüm

1
Unpack the absolute value inequality into a compound inequality
752x7-7 \le 5 - 2x \le 7
For any real constant k0k \ge 0, uk|u| \le k is equivalent to kuk-k \le u \le k.
2
Isolate the variable term by subtracting 55 from all parts of the inequality
122x2-12 \le -2x \le 2
Subtracting a constant from all parts preserves inequality direction.
3
Divide all parts by 2-2 and reverse the inequality signs
6x16 \ge x \ge -1, which is equivalent to 1x6-1 \le x \le 6
Dividing an inequality by a negative number reverses the direction of the inequality signs.
4
Find the minimum value of 34x3 - 4x over the interval [1,6][-1, 6]
The minimum value occurs at x=6x = 6: 34(6)=324=213 - 4(6) = 3 - 24 = -21
Because the linear expression 34x3 - 4x has a negative coefficient for xx, it is a decreasing function; its minimum occurs at the largest allowed value of xx.

Anahtar Kavram

Linear Inequalities and Absolute Value Bounds
Tahmini Süre:1m 30s
Soru 3Soru

If 3x612|3x - 6| \le 12, which of the following inequality ranges represents all possible values of xx?

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Cevap: 2x6-2 \le x \le 6

Cevap

2x6-2 \le x \le 6
The expression 3x612|3x - 6| \le 12 expands to the double inequality 123x612-12 \le 3x - 6 \le 12. Adding 66 to each part produces 63x18-6 \le 3x \le 18. Dividing all terms by 33 yields 2x6-2 \le x \le 6, which matches the correct solution range.

Adım Adım Çözüm

1
Rewrite the absolute value inequality as a compound inequality.
123x612-12 \le 3x - 6 \le 12
An absolute value inequality of the form uk|u| \le k (where k0k \ge 0) is equivalent to kuk-k \le u \le k.
2
Add 66 to all three parts of the inequality.
63x18-6 \le 3x \le 18
Isolate the term containing xx.
3
Divide all three parts of the inequality by 33.
2x6-2 \le x \le 6
Since 3>03 > 0, dividing by 33 isolates xx without flipping the inequality signs.

Anahtar Kavram

Solving Linear Absolute Value Inequalities
Tahmini Süre:45s
Soru 4Soru

If 2x46|2x - 4| \le 6, which of the following values could be a solution for xx? Select all that apply.

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Cevap: 1-1; 22; 55

Cevap

The values 1-1, 22, and 55 are solutions to the inequality.
Solving 2x46|2x - 4| \le 6 yields 62x46-6 \le 2x - 4 \le 6. Adding 44 gives 22x10-2 \le 2x \le 10, and dividing by 22 gives 1x5-1 \le x \le 5. The options stating 1-1, 22, and 55 are all within this interval [1,5][-1, 5].

Adım Adım Çözüm

1
Rewrite the absolute value inequality as a compound inequality.
62x46-6 \le 2x - 4 \le 6
An inequality of the form uc|u| \le c (where c0c \ge 0) is equivalent to cuc-c \le u \le c.
2
Add 44 to all three parts of the compound inequality.
22x10-2 \le 2x \le 10
Isolate the variable term 2x2x in the middle.
3
Divide all three parts by 22.
1x5-1 \le x \le 5
Isolate xx. Since 22 is positive, the inequality signs remain unchanged.
4
Test which of the given choices fall within the interval [1,5][-1, 5].
1-1, 22, and 55 lie within the range [1,5][-1, 5], while 3-3 and 66 lie outside.
Values equal to or between 1-1 and 55 inclusive are valid solutions.

Anahtar Kavram

Linear Inequalities and Absolute Value
Tahmini Süre:1m 0s
Soru 5Soru

If xx satisfies the inequality 32x>9|3 - 2x| > 9, which of the following could be the value of xx? Select all that apply.

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Cevap: 5-5; 88

Cevap

The values 5-5 and 88 satisfy the inequality.
The absolute value inequality 32x>9|3 - 2x| > 9 splits into 32x>93 - 2x > 9 or 32x<93 - 2x < -9. Solving these yields x<3x < -3 or x>6x > 6. The value 5-5 is less than 3-3 and the value 88 is greater than 66, so both are valid solutions.

Adım Adım Çözüm

1
Set up the two separate linear inequalities based on the definition of absolute value.
32x>93 - 2x > 9 or 32x<93 - 2x < -9
An absolute value expression u>c|u| > c (where c>0c > 0) breaks into two disjoint cases: u>cu > c or u<cu < -c.
2
Solve the first case: 32x>93 - 2x > 9.
2x>6    x<3-2x > 6 \implies x < -3
Subtract 3 from both sides to get 2x>6-2x > 6, then divide by 2-2 and reverse the inequality sign.
3
Solve the second case: 32x<93 - 2x < -9.
2x<12    x>6-2x < -12 \implies x > 6
Subtract 3 from both sides to get 2x<12-2x < -12, then divide by 2-2 and reverse the inequality sign.
4
Combine the solution sets and evaluate the given options.
The valid solution set is x<3x < -3 or x>6x > 6. Among the choices, 5-5 (since 5<3-5 < -3) and 88 (since 8>68 > 6) fall into the solution set.
Values between 3-3 and 66, inclusive, do not satisfy the original inequality.

Anahtar Kavram

Solving absolute value inequalities of the form u>c|u| > c by splitting into compound inequalities and reversing the direction of inequality signs when dividing by negative numbers.
Tahmini Süre:1m 15s
Soru 6Soru

If xx and yy are real numbers satisfying the inequalities 2x75|2x - 7| \le 5 and 3y+2<8|3y + 2| < 8, which of the following inequalities must be true? Select all that apply.

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Cevap: xy>1x - y > -1; xy<12xy < 12

Cevap

The inequalities that must be true are xy>1x - y > -1 and xy<12xy < 12.
Solving 2x75|2x - 7| \le 5 yields 1x61 \le x \le 6, and solving 3y+2<8|3y + 2| < 8 yields 103<y<2-\frac{10}{3} < y < 2. Combining x1x \ge 1 with y>2-y > -2 gives xy>1x - y > -1, which is always true. Furthermore, since xx is positive and bounded above by 66 while yy is bounded above by 22, the product xyxy must be strictly less than 1212.

Adım Adım Çözüm

1
Solve the absolute value inequality for xx.
52x75    22x12    1x6-5 \le 2x - 7 \le 5 \implies 2 \le 2x \le 12 \implies 1 \le x \le 6.
Unfolding the absolute value 2x75|2x - 7| \le 5 gives a compound linear inequality.
2
Solve the absolute value inequality for yy.
8<3y+2<8    10<3y<6    103<y<2-8 < 3y + 2 < 8 \implies -10 < 3y < 6 \implies -\frac{10}{3} < y < 2.
Unfolding the absolute value 3y+2<8|3y + 2| < 8 gives a strict compound linear inequality.
3
Evaluate the inequality xy>1x - y > -1.
Since x1x \ge 1 and y<2    y>2y < 2 \implies -y > -2, adding the inequalities gives x+(y)>1+(2)=1x + (-y) > 1 + (-2) = -1.
This establishes that xy>1x - y > -1 is always true.
4
Evaluate the inequality xy<12xy < 12.
Since 1x61 \le x \le 6 (all positive) and y<2y < 2, if y>0y > 0, xy<62=12xy < 6 \cdot 2 = 12. If y0y \le 0, xy0<12xy \le 0 < 12.
In all cases within the domain, xy<12xy < 12 holds strictly.
5
Test counterexamples for the remaining statements.
For x+y>0x + y > 0, x=1,y=3    x+y=20x=1, y=-3 \implies x+y=-2 \ngtr 0. For y<3|y| < 3, y=3.2    3.2=3.23y=-3.2 \implies |-3.2|=3.2 \nless 3. For yx>3y - x > -3, x=6,y=0    yx=63x=6, y=0 \implies y-x=-6 \ngtr -3.
Counterexamples disprove that these remaining statements must be true.

Anahtar Kavram

Linear Inequalities and Absolute Value Bounds
Soru 7Soru

If xx is a real number that satisfies the inequality 2x7<5|2x - 7| < 5, which of the following represents all possible values of the expression 13x1 - 3x?

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Cevap: 17<13x<2-17 < 1 - 3x < -2

Cevap

17<13x<2-17 < 1 - 3x < -2
Solving 2x7<5|2x - 7| < 5 gives 5<2x7<5-5 < 2x - 7 < 5. Adding 77 to all three parts yields 2<2x<122 < 2x < 12, which simplifies to 1<x<61 < x < 6. Multiplying this inequality by 3-3 reverses the direction of the inequalities, resulting in 18<3x<3-18 < -3x < -3. Adding 11 to each part gives 17<13x<2-17 < 1 - 3x < -2. Therefore, the range of possible values for the expression is strictly between 17-17 and 2-2.

Adım Adım Çözüm

1
Express the absolute value inequality as a compound inequality.
5<2x7<5-5 < 2x - 7 < 5
An inequality of the form u<k|u| < k for k>0k > 0 is equivalent to k<u<k-k < u < k.
2
Isolate xx in the compound inequality.
1<x<61 < x < 6
Add 77 to all parts to get 2<2x<122 < 2x < 12, then divide all parts by 22 to obtain 1<x<61 < x < 6.
3
Multiply the compound inequality by 3-3.
18<3x<3-18 < -3x < -3
Multiplying an inequality by a negative number reverses the direction of the inequality signs: 3(6)<3(x)<3(1)-3(6) < -3(x) < -3(1).
4
Add 11 to all parts of the compound inequality.
17<13x<2-17 < 1 - 3x < -2
Adding a constant to an inequality preserves the inequality direction.

Anahtar Kavram

Linear Inequalities and Absolute Value Transformations
Tahmini Süre:1m 30s
Soru 8Soru

If xx is a real number that satisfies the inequality 2x574||2x - 5| - 7| \le 4, and y=3xy = |3 - x|, what is the difference between the maximum possible value and the minimum possible value of yy?

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Cevap: 5

Cevap

The difference between the maximum possible value and the minimum possible value of yy is 5.
Solving 2x574||2x - 5| - 7| \le 4 gives 32x5113 \le |2x - 5| \le 11, which restricts xx to the disconnected domain [3,1][4,8][-3, 1] \cup [4, 8]. Evaluating y=3xy = |3 - x| across these intervals gives a maximum value of 6 (at x=3x = -3) and a minimum value of 1 (at x=4x = 4). The difference between the maximum and minimum values is 61=56 - 1 = 5.

Adım Adım Çözüm

1
Unpack the outer absolute value inequality 2x574||2x - 5| - 7| \le 4.
42x574    32x511-4 \le |2x - 5| - 7 \le 4 \implies 3 \le |2x - 5| \le 11.
An absolute value inequality ua|u| \le a (for a0a \ge 0) is equivalent to aua-a \le u \le a.
2
Solve the double inequality 32x5113 \le |2x - 5| \le 11 by splitting it into two conditions.
Condition 1: 2x511    112x511    3x8|2x - 5| \le 11 \implies -11 \le 2x - 5 \le 11 \implies -3 \le x \le 8.
Condition 2: 2x53    2x53|2x - 5| \ge 3 \implies 2x - 5 \ge 3 or 2x53    x42x - 5 \le -3 \implies x \ge 4 or x1x \le 1.
The quantity 2x5|2x - 5| must simultaneously satisfy upper and lower absolute value bounds.
3
Intersect Condition 1 and Condition 2 to determine the complete domain of xx.
x[3,1][4,8]x \in [-3, 1] \cup [4, 8].
Values in the open interval (1,4)(1, 4) make 2x5<3|2x - 5| < 3 and must be excluded from the domain.
4
Evaluate the range of y=3xy = |3 - x| over the valid domain of xx.
On [3,1][-3, 1], y=3xy = 3 - x decreases from 3(3)=63 - (-3) = 6 to 31=23 - 1 = 2, giving y[2,6]y \in [2, 6].
On [4,8][4, 8], y=x3y = x - 3 increases from 43=14 - 3 = 1 to 83=58 - 3 = 5, giving y[1,5]y \in [1, 5].
The complete range of yy is [1,6][1, 6].
Combining the output ranges of both disjoint intervals yields all possible values for yy.
5
Calculate the difference between the maximum and minimum values of yy.
Maximum y=6y = 6, Minimum y=1y = 1, Difference = 61=56 - 1 = 5.
Subtracting the minimum value 1 from the maximum value 6 gives the required difference.

Anahtar Kavram

Solving compound nested absolute value inequalities and finding the extreme values of a transformed function over disconnected solution intervals.
Tahmini Süre:2m 0s
Soru 9Soru

If xx is an integer that satisfies both 52x9|5 - 2x| \le 9 and x+1>3|x + 1| > 3, what is the least possible value of xx?

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Cevap: 3

Cevap

The least possible value of xx is 3.
Solving 52x9|5 - 2x| \le 9 gives 2x7-2 \le x \le 7. Solving x+1>3|x + 1| > 3 gives x>2x > 2 or x<4x < -4. Taking the intersection of both regions yields 2<x72 < x \le 7. The integer values satisfying this combined inequality are 3,4,5,6,3, 4, 5, 6, and 77. The smallest among these integer values is 33.

Adım Adım Çözüm

1
Solve the first absolute value inequality 52x9|5 - 2x| \le 9
2x7-2 \le x \le 7
Remove the absolute value bars to set up the compound inequality 952x9-9 \le 5 - 2x \le 9. Subtracting 55 from all parts gives 142x4-14 \le -2x \le 4. Dividing all parts by 2-2 and reversing the inequality signs yields 7x27 \ge x \ge -2, or 2x7-2 \le x \le 7.
2
Solve the second absolute value inequality x+1>3|x + 1| > 3
x>2x > 2 or x<4x < -4
Remove the absolute value bars to create two separate cases: x+1>3    x>2x + 1 > 3 \implies x > 2, or x+1<3    x<4x + 1 < -3 \implies x < -4.
3
Determine the set of values that satisfy both inequalities simultaneously
2<x72 < x \le 7
The intersection of the interval [2,7][-2, 7] and (,4)(2,)(-\infty, -4) \cup (2, \infty) is (2,7](2, 7], because x<4x < -4 does not overlap with [2,7][-2, 7].
4
Find the smallest integer within the interval (2,7](2, 7]
3
The integers included in the interval (2,7](2, 7] are 3,4,5,6,3, 4, 5, 6, and 77. Note that 22 is excluded due to the strict inequality x>2x > 2. Therefore, the least possible integer value is 33.

Anahtar Kavram

Linear Inequalities and Absolute Value
Soru 10Soru

If xx is a real number that satisfies both 3x129|3x - 12| \le 9 and 2x4|2 - x| \ge 4, the maximum possible value of the expression 52x5 - 2x is MM and the minimum possible value is mm. What is the value of MmM - m?

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Cevap: 2

Cevap

The value of MmM - m is 2.
Solving 3x129|3x - 12| \le 9 yields 1x71 \le x \le 7. Solving 2x4|2 - x| \ge 4 yields x2x \le -2 or x6x \ge 6. The set of xx-values satisfying both conditions is the intersection [6,7][6, 7]. Since 52x5 - 2x is a linear expression with a negative coefficient, its maximum value MM occurs at the smallest value of xx (x=6x = 6), giving M=52(6)=7M = 5 - 2(6) = -7. Its minimum value mm occurs at the largest value of xx (x=7x = 7), giving m=52(7)=9m = 5 - 2(7) = -9. Thus, Mm=7(9)=2M - m = -7 - (-9) = 2.

Adım Adım Çözüm

1
Solve the inequality 3x129|3x - 12| \le 9
1x71 \le x \le 7
Expanding absolute value yields 93x129-9 \le 3x - 12 \le 9. Adding 12 gives 33x213 \le 3x \le 21, then dividing by 3 yields 1x71 \le x \le 7.
2
Solve the inequality 2x4|2 - x| \ge 4
x2x \le -2 or x6x \ge 6
Absolute value inequality ua|u| \ge a splits into uau \ge a or uau \le -a. Here 2x4    x22 - x \ge 4 \implies x \le -2, and 2x4    x62 - x \le -4 \implies x \ge 6.
3
Determine the overlapping domain for xx
6x76 \le x \le 7
Combining 1x71 \le x \le 7 with x2x \le -2 or x6x \ge 6 leaves only the interval 6x76 \le x \le 7.
4
Evaluate maximum MM and minimum mm of 52x5 - 2x on 6x76 \le x \le 7
M=7M = -7 and m=9m = -9
Since 2x-2x decreases as xx increases, the maximum occurs at x=6x = 6 (M=512=7M = 5 - 12 = -7) and the minimum occurs at x=7x = 7 (m=514=9m = 5 - 14 = -9).
5
Calculate the difference MmM - m
22
Subtracting mm from MM gives 7(9)=2-7 - (-9) = 2.

Anahtar Kavram

Linear Inequalities and Absolute Value
Tahmini Süre:2m 0s
Soru 11Soru

If xx is an integer that satisfies the inequality 63x45|6 - 3x| - 4 \le 5, which of the following could be the value of xx? Select all such values.

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Cevap: 1-1; 22; 44

Cevap

The correct values of xx are 1-1, 22, and 44.
Isolating the absolute value yields 63x9|6 - 3x| \le 9, which expands to 963x9-9 \le 6 - 3x \le 9. Subtracting 66 gives 153x3-15 \le -3x \le 3. Dividing by 3-3 and reversing the inequality signs results in 1x5-1 \le x \le 5. Among the given choices, 1-1, 22, and 44 lie within this solution interval [1,5][-1, 5].

Adım Adım Çözüm

1
Isolate the absolute value expression
63x9|6 - 3x| \le 9
Add 44 to both sides of the inequality to isolate the absolute value term.
2
Rewrite as a compound inequality
963x9-9 \le 6 - 3x \le 9
The property ua|u| \le a (where a0a \ge 0) expands to aua-a \le u \le a.
3
Subtract 6 from all parts
153x3-15 \le -3x \le 3
Isolate the variable term 3x-3x by subtracting 66 across the compound inequality.
4
Divide by -3 and reverse inequality signs
5x15 \ge x \ge -1, which is equivalent to 1x5-1 \le x \le 5
Dividing an inequality by a negative quantity requires flipping the inequality direction.

Anahtar Kavram

Solving absolute value inequalities of the form ax+bc|ax + b| \le c by expanding into a compound inequality cax+bc-c \le ax + b \le c and correctly reversing inequality signs when multiplying or dividing by negative numbers.
Soru 12Soru

If xx is a real number that satisfies the inequality 52x33\left|\frac{5 - 2x}{3}\right| \le 3, what is the minimum possible value of 43x4 - 3x?

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Cevap: 17-17

Cevap

17-17
To find the minimum possible value of 43x4 - 3x, we first solve the inequality 52x33\left|\frac{5 - 2x}{3}\right| \le 3. Multiplying by 33 gives 52x9|5 - 2x| \le 9. This unfolds into the compound inequality 952x9-9 \le 5 - 2x \le 9. Subtracting 55 gives 142x4-14 \le -2x \le 4. Dividing all parts by 2-2 requires flipping the inequality signs, resulting in 7x27 \ge x \ge -2, or 2x7-2 \le x \le 7. Because 43x4 - 3x decreases as xx increases, the expression reaches its minimum when xx is at its maximum value of 77. Substituting x=7x = 7 yields 43(7)=174 - 3(7) = -17.

Adım Adım Çözüm

1
Clear the denominator from the absolute value inequality
52x9|5 - 2x| \le 9
Multiplying both sides of the inequality by the positive number 3 preserves the inequality direction.
2
Express the absolute value inequality as a compound inequality
952x9-9 \le 5 - 2x \le 9
For any non-negative constant cc, uc|u| \le c is equivalent to cuc-c \le u \le c.
3
Isolate the variable term by subtracting 5 from all parts
142x4-14 \le -2x \le 4
Subtracting a constant from all parts of a compound inequality maintains the inequality relationships.
4
Divide by -2 and reverse the inequality signs
7x2    2x77 \ge x \ge -2 \implies -2 \le x \le 7
Dividing an inequality by a negative number reverses the direction of the inequality signs.
5
Determine which bound of xx minimizes 43x4 - 3x and evaluate
Minimum value =43(7)=17= 4 - 3(7) = -17
The expression 43x4 - 3x has a negative coefficient for xx, making it a decreasing function. Therefore, the minimum value of 43x4 - 3x occurs when xx takes its maximum possible value (x=7x = 7).

Anahtar Kavram

Linear Inequalities and Absolute Value
Soru 13Soru

If xx is an integer that satisfies both 2x59|2x - 5| \le 9 and 3x<53 - x < 5, how many possible values of xx exist?

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Cevap: 9

Cevap

There are 9 possible integer values for x.
Solving 2x59|2x - 5| \le 9 gives 2x7-2 \le x \le 7. Solving 3x<53 - x < 5 gives x>2x > -2. Taking the intersection yields 2<x7-2 < x \le 7. The integers in this interval are 1,0,1,2,3,4,5,6,7-1, 0, 1, 2, 3, 4, 5, 6, 7, amounting to 9 values in total.

Adım Adım Çözüm

1
Solve the absolute value inequality 2x59|2x - 5| \le 9
2x7-2 \le x \le 7
Unfold 2x59|2x - 5| \le 9 as 92x59-9 \le 2x - 5 \le 9, add 5 to obtain 42x14-4 \le 2x \le 14, and divide by 2.
2
Solve the linear inequality 3x<53 - x < 5
x>2x > -2
Subtract 3 to get x<2-x < 2, then divide by 1-1 and reverse the inequality symbol.
3
Determine the intersection of both inequalities
2<x7-2 < x \le 7
Combine 2x7-2 \le x \le 7 and x>2x > -2 on the real number line.
4
Count the integer values within the intersection 2<x7-2 < x \le 7
9 integer values
The valid integers are 1,0,1,2,3,4,5,6,7-1, 0, 1, 2, 3, 4, 5, 6, 7, giving a total count of 7(1)+1=97 - (-1) + 1 = 9.

Anahtar Kavram

Linear Inequalities and Absolute Value Bounds
Tahmini Süre:1m 30s
Soru 14Soru

How many integer values of xx satisfy the compound absolute value inequality 1x4351 \le ||x - 4| - 3| \le 5?

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Cevap: 15

Cevap

There are 15 integer values of xx that satisfy the given compound inequality.
Solving 1x4351 \le ||x - 4| - 3| \le 5 requires breaking the nested absolute value into its boundary constraints. The upper bound x435\|x - 4| - 3| \le 5 restricts xx to [4,12][-4, 12]. The lower bound x431||x - 4| - 3| \ge 1 requires either x44|x - 4| \ge 4 (giving x0x \le 0 or x8x \ge 8) or x42|x - 4| \le 2 (giving 2x62 \le x \le 6). Taking the intersection produces three distinct inclusive integer intervals: [4,0][-4, 0], [2,6][2, 6], and [8,12][8, 12]. Each interval contains 5 integers, yielding a total of 15 integer solutions.

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1
Decompose the double inequality into two separate absolute value inequalities: x435||x - 4| - 3| \le 5 and x431||x - 4| - 3| \ge 1.
Two simultaneous inequalities to solve for xx.
A double inequality auba \le |u| \le b requires satisfying both ub|u| \le b and ua|u| \ge a.
2
Solve the upper bound inequality x435||x - 4| - 3| \le 5.
5x435    2x48-5 \le |x - 4| - 3 \le 5 \implies -2 \le |x - 4| \le 8. Since x402|x - 4| \ge 0 \ge -2 is always true, this simplifies to x48    4x12|x - 4| \le 8 \implies -4 \le x \le 12.
Absolute value is non-negative, so the lower bound of 2-2 imposes no extra constraint.
3
Solve the lower bound inequality x431||x - 4| - 3| \ge 1.
This splits into two cases: x431|x - 4| - 3 \ge 1 OR x431|x - 4| - 3 \le -1.
Case A: x44    x44|x - 4| \ge 4 \implies x - 4 \ge 4 or x44    x8x - 4 \le -4 \implies x \ge 8 or x0x \le 0.
Case B: x42    2x42    2x6|x - 4| \le 2 \implies -2 \le x - 4 \le 2 \implies 2 \le x \le 6.
The absolute value inequality u1|u| \ge 1 holds when u1u \ge 1 or u1u \le -1.
4
Intersect the solution set from the upper bound [4,12][-4, 12] with the solution set from the lower bound (,0][2,6][8,)(-\infty, 0] \cup [2, 6] \cup [8, \infty).
The valid solution set is x[4,0][2,6][8,12]x \in [-4, 0] \cup [2, 6] \cup [8, 12].
Both conditions must hold simultaneously.
5
Count the integer values in each of the three valid intervals.
Interval [4,0][-4, 0] has 5 integers: {4,3,2,1,0}\{-4, -3, -2, -1, 0\}.
Interval [2,6][2, 6] has 5 integers: {2,3,4,5,6}\{2, 3, 4, 5, 6\}.
Interval [8,12][8, 12] has 5 integers: {8,9,10,11,12}\{8, 9, 10, 11, 12\}.
Total integer solutions = 5+5+5=155 + 5 + 5 = 15.
The number of integers in an inclusive integer range [a,b][a, b] is ba+1b - a + 1.

Anahtar Kavram

Linear Inequalities and Absolute Value
Soru 15Soru

If xx is a real number such that 43x13|4 - 3x| \leq 13, and yy is an integer such that 5<12y33-5 < \frac{1 - 2y}{3} \leq 3, what is the least possible integer value of x2yx^2 - y?

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Cevap: 7-7

Cevap

The least possible integer value of x2yx^2 - y is 7-7.
To find the minimum value of x2yx^2 - y, we must minimize x2x^2 and maximize yy. The absolute value inequality 43x13|4 - 3x| \leq 13 simplifies to 3x173-3 \leq x \leq \frac{17}{3}, which contains 00, so the minimum of x2x^2 is 00. The inequality 5<12y33-5 < \frac{1 - 2y}{3} \leq 3 simplifies to 4y<8-4 \leq y < 8. Since yy is an integer, its maximum value is 77. Therefore, the minimum possible value of x2yx^2 - y is 07=70 - 7 = -7.

Adım Adım Çözüm

1
Solve the absolute value inequality 43x13|4 - 3x| \leq 13 for xx.
1343x13    173x9    173x3    3x173-13 \leq 4 - 3x \leq 13 \implies -17 \leq -3x \leq 9 \implies \frac{17}{3} \geq x \geq -3 \implies -3 \leq x \leq \frac{17}{3}.
An absolute value inequality uk|u| \leq k expands to kuk-k \leq u \leq k. Dividing by a negative number flips the inequality signs.
2
Determine the minimum possible value of x2x^2.
Minimum x2=0x^2 = 0.
Since xx can take any real value in the interval [3,173][-3, \frac{17}{3}], which contains 00, the minimum square of any real number in this interval is 00 at x=0x = 0.
3
Solve the double inequality 5<12y33-5 < \frac{1 - 2y}{3} \leq 3 for yy.
15<12y9    16<2y8    8>y4    4y<8-15 < 1 - 2y \leq 9 \implies -16 < -2y \leq 8 \implies 8 > y \geq -4 \implies -4 \leq y < 8.
Multiplying by 33 preserves inequalities, subtracting 11 preserves inequalities, and dividing by 2-2 reverses all inequality signs.
4
Find the maximum integer value of yy.
Maximum integer y=7y = 7.
The solution set for yy is the half-open interval [4,8)[-4, 8). Since yy is constrained to be an integer, the largest integer strictly less than 88 is 77.
5
Minimize the expression x2yx^2 - y.
Minimum (x2y)=Minimum (x2)Maximum (y)=07=7\text{Minimum } (x^2 - y) = \text{Minimum } (x^2) - \text{Maximum } (y) = 0 - 7 = -7.
To minimize a difference ABA - B, one must minimize the minuend AA and maximize the subtrahend BB.

Anahtar Kavram

Linear Inequalities and Absolute Value
Tahmini Süre:2m 0s
Soru 16Soru

If 3x2+4>11-3|x - 2| + 4 > -11, which of the following inequalities represents all possible real values of xx?

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Cevap: 3<x<7-3 < x < 7

Cevap

3<x<7-3 < x < 7
Subtracting 44 from both sides gives 3x2>15-3|x - 2| > -15. Dividing by 3-3 and reversing the inequality sign results in x2<5|x - 2| < 5. Converting to the compound inequality 5<x2<5-5 < x - 2 < 5 and adding 22 to each part yields the correct interval 3<x<7-3 < x < 7.

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1
Subtract 4 from both sides of the inequality
3x2>15-3|x - 2| > -15
Isolate the absolute value term on the left side.
2
Divide both sides by 3-3 and reverse the inequality sign
x2<5|x - 2| < 5
Dividing an inequality by a negative number reverses the direction of the inequality symbol.
3
Express the absolute value inequality as a compound inequality
5<x2<5-5 < x - 2 < 5
An inequality of the form u<c|u| < c (where c>0c > 0) is equivalent to c<u<c-c < u < c.
4
Add 2 to all three parts of the compound inequality
3<x<7-3 < x < 7
Isolate xx to find the complete range of solution values.

Anahtar Kavram

Linear Inequalities and Absolute Value
Soru 17Soru

Which of the following values of xx satisfy the inequality 2x15x|2x - 1| \le 5 - x? Select all that apply.

Geçerli olan tümünü seçin

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Cevap: 4-4; 1-1; 11

Cevap

The values of xx that satisfy the inequality are 4-4, 1-1, and 11.
Solving the compound inequality (5x)2x15x-(5 - x) \le 2x - 1 \le 5 - x yields the solution range 4x2-4 \le x \le 2. The candidate values 4-4, 1-1, and 11 all lie within this range, making them valid solutions.

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1
Determine the non-negativity constraint for the right-hand side expression.
Since an absolute value 2x1|2x - 1| must be non-negative, we must have 5x05 - x \ge 0, which simplifies to x5x \le 5.
An absolute value cannot be less than a negative number.
2
Rewrite the absolute value inequality 2x15x|2x - 1| \le 5 - x as a compound linear inequality.
(5x)2x15x-(5 - x) \le 2x - 1 \le 5 - x, which expands to 5+x2x15x-5 + x \le 2x - 1 \le 5 - x.
For any non-negative expression BB, AB|A| \le B is logically equivalent to BAB-B \le A \le B.
3
Solve the left-hand inequality 5+x2x1-5 + x \le 2x - 1.
Subtracting xx from both sides gives 5x1-5 \le x - 1. Adding 11 to both sides yields x4x \ge -4.
Isolating xx establishes the lower bound of the solution set.
4
Solve the right-hand inequality 2x15x2x - 1 \le 5 - x.
Adding xx to both sides gives 3x153x - 1 \le 5. Adding 11 yields 3x63x \le 6, so x2x \le 2.
Isolating xx establishes the upper bound of the solution set.
5
Intersect all constraints to find the valid domain for xx.
Combining x4x \ge -4, x2x \le 2, and x5x \le 5 gives the closed interval [4,2][-4, 2].
A valid value of xx must satisfy all component inequalities simultaneously.
6
Evaluate the candidate choices against the solution interval [4,2][-4, 2].
The values 4-4, 1-1, and 11 fall within [4,2][-4, 2], whereas 33 and 5-5 fall outside this interval.
Only numbers inside [4,2][-4, 2] satisfy the original inequality.

Anahtar Kavram

Solving Absolute Value Inequalities with Variable Expressions
Soru 18Soru

If xx is a real number that satisfies both of the inequalities 3x+411|3x + 4| \ge 11 and x1<6|x - 1| < 6, which of the following could be the value of xx? Select all that apply.

Geçerli olan tümünü seçin

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Cevap: 33; 55

Cevap

The values 3 and 5 satisfy both inequalities.
Solving the first inequality 3x+411|3x + 4| \ge 11 yields x5x \le -5 or x73x \ge \frac{7}{3}. Solving the second inequality x1<6|x - 1| < 6 yields 5<x<7-5 < x < 7. Intersecting these two regions, the interval x5x \le -5 does not overlap with 5<x<7-5 < x < 7 because 5-5 is excluded from the second inequality. The overlap occurs only for 73x<7\frac{7}{3} \le x < 7. Among the choices, 3 and 5 fall within this valid interval.

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1
Solve the absolute value inequality 3x+411|3x + 4| \ge 11.
x5x \le -5 or x73x \ge \frac{7}{3}.
An absolute value inequality of the form uk|u| \ge k (where k>0k > 0) splits into two separate inequalities: uku \ge k or uku \le -k. Solving 3x+4113x + 4 \ge 11 gives 3x7    x733x \ge 7 \implies x \ge \frac{7}{3}. Solving 3x+4113x + 4 \le -11 gives 3x15    x53x \le -15 \implies x \le -5.
2
Solve the absolute value inequality x1<6|x - 1| < 6.
5<x<7-5 < x < 7.
An absolute value inequality of the form u<k|u| < k is equivalent to the compound inequality k<u<k-k < u < k. Thus, 6<x1<6-6 < x - 1 < 6. Adding 1 to all parts yields 5<x<7-5 < x < 7.
3
Determine the intersection of the two solution sets.
73x<7\frac{7}{3} \le x < 7.
The portion x5x \le -5 has no overlap with 5<x<7-5 < x < 7 because 5-5 is excluded by the strict inequality in the second condition. The portion x73x \ge \frac{7}{3} overlaps with 5<x<7-5 < x < 7 to yield the interval [73,7)[\frac{7}{3}, 7).
4
Evaluate which of the given options fall inside [73,7)[\frac{7}{3}, 7).
The numbers 3 and 5 belong to the interval, while 5-5, 3-3, and 77 do not.
Since 732.33\frac{7}{3} \approx 2.33, the values 3 and 5 fall strictly between 2.33 and 7.

Anahtar Kavram

Solving systems of linear absolute value inequalities by finding the intersection of compound solution intervals
Soru 19Soru

If xx is a real number that satisfies both 32x5|3 - 2x| \ge 5 and 73x2>1\frac{7 - 3x}{-2} > -1, which of the following expresses all possible values of xx?

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Cevap: x4x \ge 4

Cevap

The condition is satisfied by all values of xx such that x4x \ge 4.
Solving 32x5|3 - 2x| \ge 5 yields two separate intervals: x1x \le -1 or x4x \ge 4. Solving 73x2>1\frac{7 - 3x}{-2} > -1 involves multiplying by 2-2 and dividing by 3-3, both of which flip the inequality sign, leading to x>53x > \frac{5}{3}. The values of xx that satisfy both constraints are those in the overlap of x(,1][4,)x \in (-\infty, -1] \cup [4, \infty) and x>53x > \frac{5}{3}, which simplifies directly to x4x \ge 4.

Adım Adım Çözüm

1
Solve the absolute value inequality 32x5|3 - 2x| \ge 5.
Splitting into two cases: 32x5    2x2    x13 - 2x \ge 5 \implies -2x \ge 2 \implies x \le -1, or 32x5    2x8    x43 - 2x \le -5 \implies -2x \le -8 \implies x \ge 4. So x(,1][4,)x \in (-\infty, -1] \cup [4, \infty).
An absolute value inequality uk|u| \ge k (for k>0k > 0) decouples into uku \ge k or uku \le -k.
2
Solve the linear inequality 73x2>1\frac{7 - 3x}{-2} > -1.
Multiply both sides by 2-2 (reversing the inequality): 73x<27 - 3x < 2. Subtract 7: 3x<5-3x < -5. Divide by 3-3 (reversing the inequality again): x>53x > \frac{5}{3}.
Multiplying or dividing an inequality by a negative quantity reverses the direction of the inequality sign.
3
Find the intersection of the two solution sets.
We require x((,1][4,))(53,)x \in ((-\infty, -1] \cup [4, \infty)) \cap (\frac{5}{3}, \infty). Since (,1](-\infty, -1] has no overlap with (53,)(\frac{5}{3}, \infty), the intersection is [4,)[4, \infty), or x4x \ge 4.
A real number must satisfy both inequalities simultaneously.

Anahtar Kavram

Solving systems of absolute value and linear inequalities with negative multipliers
Soru 20Soru

If xx is an integer that satisfies both 4x513|4x - 5| \le 13 and 2x131\frac{2x - 1}{-3} \le -1, what is the sum of all possible values of xx?

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Cevap: 9

Cevap

9
Solving the absolute value inequality 4x513|4x - 5| \le 13 yields 134x513-13 \le 4x - 5 \le 13, which simplifies to 2x4.5-2 \le x \le 4.5. Next, solving 2x131\frac{2x - 1}{-3} \le -1 requires multiplying both sides by 3-3 and reversing the inequality sign, giving 2x132x - 1 \ge 3, which simplifies to x2x \ge 2. Combining 2x4.5-2 \le x \le 4.5 and x2x \ge 2 for integer xx gives the set {2,3,4}\{2, 3, 4\}. The sum of these values is 2+3+4=92 + 3 + 4 = 9.

Adım Adım Çözüm

1
Solve the absolute value inequality 4x513|4x - 5| \le 13
-13 \le 4x - 5 \le 13 \implies -8 \le 4x \le 18 \implies -2 \le x \le 4.5
An absolute value inequality uk|u| \le k unfolds into the compound inequality kuk-k \le u \le k.
2
Solve the linear inequality 2x131\frac{2x - 1}{-3} \le -1
2x - 1 \ge 3 \implies 2x \ge 4 \implies x \ge 2
Multiplying or dividing both sides of an inequality by a negative number reverses the direction of the inequality sign.
3
Find the intersection of the two solution sets for integer xx
x \in \{2, 3, 4\}
The integers satisfying both 2x4.5-2 \le x \le 4.5 and x2x \ge 2 are 2, 3, and 4.
4
Calculate the sum of the possible integer values
2 + 3 + 4 = 9
Summing the valid integer solutions yields the final requested answer.

Anahtar Kavram

Linear Inequalities and Absolute Value
Tahmini Süre:2m 0s
Sayfa 1 / 3Sonraki