Linear Inequalities and Absolute Value

52 soru

Soru 1Soru →

If xx is a real number that satisfies the compound absolute value inequality ∣∣2x−5∣−7∣≤4||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 ∣∣2x−5∣−7∣≤4||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.
−4≤∣2x−5∣−7≤4-4 \le |2x - 5| - 7 \le 4
For any expression UU and constant c≥0c \ge 0, ∣U∣≤c|U| \le c is equivalent to −c≤U≤c-c \le U \le c.
2
Isolate the inner absolute value term by adding 77 across all parts.
3≤∣2x−5∣≤113 \le |2x - 5| \le 11
Adding a constant preserves inequality directions.
3
Break the compound inequality into two separate absolute value conditions.
Condition 1: ∣2x−5∣≤11|2x - 5| \le 11; Condition 2: ∣2x−5∣≥3|2x - 5| \ge 3
Both conditions must hold simultaneously for xx.
4
Solve Condition 1 (∣2x−5∣≤11|2x - 5| \le 11).
−11≤2x−5≤11  ⟹  −6≤2x≤16  ⟹  −3≤x≤8-11 \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 (∣2x−5∣≥3|2x - 5| \ge 3).
2x−5≥32x - 5 \ge 3 or 2x−5≤−3  ⟹  2x≥82x - 5 \le -3 \implies 2x \ge 8 or 2x≤2  ⟹  x≥42x \le 2 \implies x \ge 4 or x≤1x \le 1
For ∣U∣≥c|U| \ge c, U≥cU \ge c or U≤−cU \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 ∣5−2x∣≤7|5 - 2x| \le 7, what is the minimum possible value of the expression 3−4x3 - 4x?

Cevabı ve açıklamayı göster

Cevap: −21-21

Cevap

−21-21
Solving ∣5−2x∣≤7|5 - 2x| \le 7 yields −7≤5−2x≤7-7 \le 5 - 2x \le 7. Subtracting 55 gives −12≤−2x≤2-12 \le -2x \le 2. Dividing by −2-2 and flipping the inequality direction gives −1≤x≤6-1 \le x \le 6. To minimize 3−4x3 - 4x, we choose the maximum value of xx because the term −4x-4x decreases as xx increases. Substituting x=6x = 6 yields 3−4(6)=−213 - 4(6) = -21.

Adım Adım Çözüm

1
Unpack the absolute value inequality into a compound inequality
−7≤5−2x≤7-7 \le 5 - 2x \le 7
For any real constant k≥0k \ge 0, ∣u∣≤k|u| \le k is equivalent to −k≤u≤k-k \le u \le k.
2
Isolate the variable term by subtracting 55 from all parts of the inequality
−12≤−2x≤2-12 \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
6≥x≥−16 \ge x \ge -1, which is equivalent to −1≤x≤6-1 \le x \le 6
Dividing an inequality by a negative number reverses the direction of the inequality signs.
4
Find the minimum value of 3−4x3 - 4x over the interval [−1,6][-1, 6]
The minimum value occurs at x=6x = 6: 3−4(6)=3−24=−213 - 4(6) = 3 - 24 = -21
Because the linear expression 3−4x3 - 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 ∣3x−6∣≤12|3x - 6| \le 12, which of the following inequality ranges represents all possible values of xx?

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Cevap: −2≤x≤6-2 \le x \le 6

Cevap

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

Adım Adım Çözüm

1
Rewrite the absolute value inequality as a compound inequality.
−12≤3x−6≤12-12 \le 3x - 6 \le 12
An absolute value inequality of the form ∣u∣≤k|u| \le k (where k≥0k \ge 0) is equivalent to −k≤u≤k-k \le u \le k.
2
Add 66 to all three parts of the inequality.
−6≤3x≤18-6 \le 3x \le 18
Isolate the term containing xx.
3
Divide all three parts of the inequality by 33.
−2≤x≤6-2 \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 ∣2x−4∣≤6|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 ∣2x−4∣≤6|2x - 4| \le 6 yields −6≤2x−4≤6-6 \le 2x - 4 \le 6. Adding 44 gives −2≤2x≤10-2 \le 2x \le 10, and dividing by 22 gives −1≤x≤5-1 \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.
−6≤2x−4≤6-6 \le 2x - 4 \le 6
An inequality of the form ∣u∣≤c|u| \le c (where c≥0c \ge 0) is equivalent to −c≤u≤c-c \le u \le c.
2
Add 44 to all three parts of the compound inequality.
−2≤2x≤10-2 \le 2x \le 10
Isolate the variable term 2x2x in the middle.
3
Divide all three parts by 22.
−1≤x≤5-1 \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 ∣3−2x∣>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 ∣3−2x∣>9|3 - 2x| > 9 splits into 3−2x>93 - 2x > 9 or 3−2x<−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.
3−2x>93 - 2x > 9 or 3−2x<−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: 3−2x>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: 3−2x<−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 ∣2x−7∣≤5|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: x−y>−1x - y > -1; xy<12xy < 12

Cevap

The inequalities that must be true are x−y>−1x - y > -1 and xy<12xy < 12.
Solving ∣2x−7∣≤5|2x - 7| \le 5 yields 1≤x≤61 \le x \le 6, and solving ∣3y+2∣<8|3y + 2| < 8 yields −103<y<2-\frac{10}{3} < y < 2. Combining x≥1x \ge 1 with −y>−2-y > -2 gives x−y>−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.
−5≤2x−7≤5  ⟹  2≤2x≤12  ⟹  1≤x≤6-5 \le 2x - 7 \le 5 \implies 2 \le 2x \le 12 \implies 1 \le x \le 6.
Unfolding the absolute value ∣2x−7∣≤5|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 x−y>−1x - y > -1.
Since x≥1x \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 x−y>−1x - y > -1 is always true.
4
Evaluate the inequality xy<12xy < 12.
Since 1≤x≤61 \le x \le 6 (all positive) and y<2y < 2, if y>0y > 0, xy<6⋅2=12xy < 6 \cdot 2 = 12. If y≤0y \le 0, xy≤0<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=−2≯0x=1, y=-3 \implies x+y=-2 \ngtr 0. For ∣y∣<3|y| < 3, y=−3.2  ⟹  ∣−3.2∣=3.2≮3y=-3.2 \implies |-3.2|=3.2 \nless 3. For y−x>−3y - x > -3, x=6,y=0  ⟹  y−x=−6≯−3x=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 ∣2x−7∣<5|2x - 7| < 5, which of the following represents all possible values of the expression 1−3x1 - 3x?

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Cevap: −17<1−3x<−2-17 < 1 - 3x < -2

Cevap

−17<1−3x<−2-17 < 1 - 3x < -2
Solving ∣2x−7∣<5|2x - 7| < 5 gives −5<2x−7<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<1−3x<−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<2x−7<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<1−3x<−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 ∣∣2x−5∣−7∣≤4||2x - 5| - 7| \le 4, and y=∣3−x∣y = |3 - x|, what is the difference between the maximum possible value and the minimum possible value of yy?

Cevabı ve açıklamayı göster

Cevap: 5

Cevap

The difference between the maximum possible value and the minimum possible value of yy is 5.
Solving ∣∣2x−5∣−7∣≤4||2x - 5| - 7| \le 4 gives 3≤∣2x−5∣≤113 \le |2x - 5| \le 11, which restricts xx to the disconnected domain [−3,1]∪[4,8][-3, 1] \cup [4, 8]. Evaluating y=∣3−x∣y = |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 6−1=56 - 1 = 5.

Adım Adım Çözüm

1
Unpack the outer absolute value inequality ∣∣2x−5∣−7∣≤4||2x - 5| - 7| \le 4.
−4≤∣2x−5∣−7≤4  ⟹  3≤∣2x−5∣≤11-4 \le |2x - 5| - 7 \le 4 \implies 3 \le |2x - 5| \le 11.
An absolute value inequality ∣u∣≤a|u| \le a (for a≥0a \ge 0) is equivalent to −a≤u≤a-a \le u \le a.
2
Solve the double inequality 3≤∣2x−5∣≤113 \le |2x - 5| \le 11 by splitting it into two conditions.
Condition 1: ∣2x−5∣≤11  ⟹  −11≤2x−5≤11  ⟹  −3≤x≤8|2x - 5| \le 11 \implies -11 \le 2x - 5 \le 11 \implies -3 \le x \le 8.
Condition 2: ∣2x−5∣≥3  ⟹  2x−5≥3|2x - 5| \ge 3 \implies 2x - 5 \ge 3 or 2x−5≤−3  ⟹  x≥42x - 5 \le -3 \implies x \ge 4 or x≤1x \le 1.
The quantity ∣2x−5∣|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 ∣2x−5∣<3|2x - 5| < 3 and must be excluded from the domain.
4
Evaluate the range of y=∣3−x∣y = |3 - x| over the valid domain of xx.
On [−3,1][-3, 1], y=3−xy = 3 - x decreases from 3−(−3)=63 - (-3) = 6 to 3−1=23 - 1 = 2, giving y∈[2,6]y \in [2, 6].
On [4,8][4, 8], y=x−3y = x - 3 increases from 4−3=14 - 3 = 1 to 8−3=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 = 6−1=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 ∣5−2x∣≤9|5 - 2x| \le 9 and ∣x+1∣>3|x + 1| > 3, what is the least possible value of xx?

Cevabı ve açıklamayı göster

Cevap: 3

Cevap

The least possible value of xx is 3.
Solving ∣5−2x∣≤9|5 - 2x| \le 9 gives −2≤x≤7-2 \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<x≤72 < 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 ∣5−2x∣≤9|5 - 2x| \le 9
−2≤x≤7-2 \le x \le 7
Remove the absolute value bars to set up the compound inequality −9≤5−2x≤9-9 \le 5 - 2x \le 9. Subtracting 55 from all parts gives −14≤−2x≤4-14 \le -2x \le 4. Dividing all parts by −2-2 and reversing the inequality signs yields 7≥x≥−27 \ge x \ge -2, or −2≤x≤7-2 \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<x≤72 < 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 ∣3x−12∣≤9|3x - 12| \le 9 and ∣2−x∣≥4|2 - x| \ge 4, the maximum possible value of the expression 5−2x5 - 2x is MM and the minimum possible value is mm. What is the value of M−mM - m?

Cevabı ve açıklamayı göster

Cevap: 2

Cevap

The value of M−mM - m is 2.
Solving ∣3x−12∣≤9|3x - 12| \le 9 yields 1≤x≤71 \le x \le 7. Solving ∣2−x∣≥4|2 - x| \ge 4 yields x≤−2x \le -2 or x≥6x \ge 6. The set of xx-values satisfying both conditions is the intersection [6,7][6, 7]. Since 5−2x5 - 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=5−2(6)=−7M = 5 - 2(6) = -7. Its minimum value mm occurs at the largest value of xx (x=7x = 7), giving m=5−2(7)=−9m = 5 - 2(7) = -9. Thus, M−m=−7−(−9)=2M - m = -7 - (-9) = 2.

Adım Adım Çözüm

1
Solve the inequality ∣3x−12∣≤9|3x - 12| \le 9
1≤x≤71 \le x \le 7
Expanding absolute value yields −9≤3x−12≤9-9 \le 3x - 12 \le 9. Adding 12 gives 3≤3x≤213 \le 3x \le 21, then dividing by 3 yields 1≤x≤71 \le x \le 7.
2
Solve the inequality ∣2−x∣≥4|2 - x| \ge 4
x≤−2x \le -2 or x≥6x \ge 6
Absolute value inequality ∣u∣≥a|u| \ge a splits into u≥au \ge a or u≤−au \le -a. Here 2−x≥4  ⟹  x≤−22 - x \ge 4 \implies x \le -2, and 2−x≤−4  ⟹  x≥62 - x \le -4 \implies x \ge 6.
3
Determine the overlapping domain for xx
6≤x≤76 \le x \le 7
Combining 1≤x≤71 \le x \le 7 with x≤−2x \le -2 or x≥6x \ge 6 leaves only the interval 6≤x≤76 \le x \le 7.
4
Evaluate maximum MM and minimum mm of 5−2x5 - 2x on 6≤x≤76 \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=5−12=−7M = 5 - 12 = -7) and the minimum occurs at x=7x = 7 (m=5−14=−9m = 5 - 14 = -9).
5
Calculate the difference M−mM - 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 ∣6−3x∣−4≤5|6 - 3x| - 4 \le 5, which of the following could be the value of xx? Select all such values.

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Cevabı ve açıklamayı göster

Cevap: −1-1; 22; 44

Cevap

The correct values of xx are −1-1, 22, and 44.
Isolating the absolute value yields ∣6−3x∣≤9|6 - 3x| \le 9, which expands to −9≤6−3x≤9-9 \le 6 - 3x \le 9. Subtracting 66 gives −15≤−3x≤3-15 \le -3x \le 3. Dividing by −3-3 and reversing the inequality signs results in −1≤x≤5-1 \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
∣6−3x∣≤9|6 - 3x| \le 9
Add 44 to both sides of the inequality to isolate the absolute value term.
2
Rewrite as a compound inequality
−9≤6−3x≤9-9 \le 6 - 3x \le 9
The property ∣u∣≤a|u| \le a (where a≥0a \ge 0) expands to −a≤u≤a-a \le u \le a.
3
Subtract 6 from all parts
−15≤−3x≤3-15 \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
5≥x≥−15 \ge x \ge -1, which is equivalent to −1≤x≤5-1 \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+b∣≤c|ax + b| \le c by expanding into a compound inequality −c≤ax+b≤c-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 ∣5−2x3∣≤3\left|\frac{5 - 2x}{3}\right| \le 3, what is the minimum possible value of 4−3x4 - 3x?

Cevabı ve açıklamayı göster

Cevap: −17-17

Cevap

−17-17
To find the minimum possible value of 4−3x4 - 3x, we first solve the inequality ∣5−2x3∣≤3\left|\frac{5 - 2x}{3}\right| \le 3. Multiplying by 33 gives ∣5−2x∣≤9|5 - 2x| \le 9. This unfolds into the compound inequality −9≤5−2x≤9-9 \le 5 - 2x \le 9. Subtracting 55 gives −14≤−2x≤4-14 \le -2x \le 4. Dividing all parts by −2-2 requires flipping the inequality signs, resulting in 7≥x≥−27 \ge x \ge -2, or −2≤x≤7-2 \le x \le 7. Because 4−3x4 - 3x decreases as xx increases, the expression reaches its minimum when xx is at its maximum value of 77. Substituting x=7x = 7 yields 4−3(7)=−174 - 3(7) = -17.

Adım Adım Çözüm

1
Clear the denominator from the absolute value inequality
∣5−2x∣≤9|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
−9≤5−2x≤9-9 \le 5 - 2x \le 9
For any non-negative constant cc, ∣u∣≤c|u| \le c is equivalent to −c≤u≤c-c \le u \le c.
3
Isolate the variable term by subtracting 5 from all parts
−14≤−2x≤4-14 \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
7≥x≥−2  ⟹  −2≤x≤77 \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 4−3x4 - 3x and evaluate
Minimum value =4−3(7)=−17= 4 - 3(7) = -17
The expression 4−3x4 - 3x has a negative coefficient for xx, making it a decreasing function. Therefore, the minimum value of 4−3x4 - 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 ∣2x−5∣≤9|2x - 5| \le 9 and 3−x<53 - x < 5, how many possible values of xx exist?

Cevabı ve açıklamayı göster

Cevap: 9

Cevap

There are 9 possible integer values for x.
Solving ∣2x−5∣≤9|2x - 5| \le 9 gives −2≤x≤7-2 \le x \le 7. Solving 3−x<53 - x < 5 gives x>−2x > -2. Taking the intersection yields −2<x≤7-2 < 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 ∣2x−5∣≤9|2x - 5| \le 9
−2≤x≤7-2 \le x \le 7
Unfold ∣2x−5∣≤9|2x - 5| \le 9 as −9≤2x−5≤9-9 \le 2x - 5 \le 9, add 5 to obtain −4≤2x≤14-4 \le 2x \le 14, and divide by 2.
2
Solve the linear inequality 3−x<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<x≤7-2 < x \le 7
Combine −2≤x≤7-2 \le x \le 7 and x>−2x > -2 on the real number line.
4
Count the integer values within the intersection −2<x≤7-2 < 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 1≤∣∣x−4∣−3∣≤51 \le ||x - 4| - 3| \le 5?

Cevabı ve açıklamayı göster

Cevap: 15

Cevap

There are 15 integer values of xx that satisfy the given compound inequality.
Solving 1≤∣∣x−4∣−3∣≤51 \le ||x - 4| - 3| \le 5 requires breaking the nested absolute value into its boundary constraints. The upper bound ∥x−4∣−3∣≤5\|x - 4| - 3| \le 5 restricts xx to [−4,12][-4, 12]. The lower bound ∣∣x−4∣−3∣≥1||x - 4| - 3| \ge 1 requires either ∣x−4∣≥4|x - 4| \ge 4 (giving x≤0x \le 0 or x≥8x \ge 8) or ∣x−4∣≤2|x - 4| \le 2 (giving 2≤x≤62 \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.

Adım Adım Çözüm

1
Decompose the double inequality into two separate absolute value inequalities: ∣∣x−4∣−3∣≤5||x - 4| - 3| \le 5 and ∣∣x−4∣−3∣≥1||x - 4| - 3| \ge 1.
Two simultaneous inequalities to solve for xx.
A double inequality a≤∣u∣≤ba \le |u| \le b requires satisfying both ∣u∣≤b|u| \le b and ∣u∣≥a|u| \ge a.
2
Solve the upper bound inequality ∣∣x−4∣−3∣≤5||x - 4| - 3| \le 5.
−5≤∣x−4∣−3≤5  ⟹  −2≤∣x−4∣≤8-5 \le |x - 4| - 3 \le 5 \implies -2 \le |x - 4| \le 8. Since ∣x−4∣≥0≥−2|x - 4| \ge 0 \ge -2 is always true, this simplifies to ∣x−4∣≤8  ⟹  −4≤x≤12|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 ∣∣x−4∣−3∣≥1||x - 4| - 3| \ge 1.
This splits into two cases: ∣x−4∣−3≥1|x - 4| - 3 \ge 1 OR ∣x−4∣−3≤−1|x - 4| - 3 \le -1.
Case A: ∣x−4∣≥4  ⟹  x−4≥4|x - 4| \ge 4 \implies x - 4 \ge 4 or x−4≤−4  ⟹  x≥8x - 4 \le -4 \implies x \ge 8 or x≤0x \le 0.
Case B: ∣x−4∣≤2  ⟹  −2≤x−4≤2  ⟹  2≤x≤6|x - 4| \le 2 \implies -2 \le x - 4 \le 2 \implies 2 \le x \le 6.
The absolute value inequality ∣u∣≥1|u| \ge 1 holds when u≥1u \ge 1 or u≤−1u \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 b−a+1b - a + 1.

Anahtar Kavram

Linear Inequalities and Absolute Value
Soru 15Soru →

If xx is a real number such that ∣4−3x∣≤13|4 - 3x| \leq 13, and yy is an integer such that −5<1−2y3≤3-5 < \frac{1 - 2y}{3} \leq 3, what is the least possible integer value of x2−yx^2 - y?

Cevabı ve açıklamayı göster

Cevap: −7-7

Cevap

The least possible integer value of x2−yx^2 - y is −7-7.
To find the minimum value of x2−yx^2 - y, we must minimize x2x^2 and maximize yy. The absolute value inequality ∣4−3x∣≤13|4 - 3x| \leq 13 simplifies to −3≤x≤173-3 \leq x \leq \frac{17}{3}, which contains 00, so the minimum of x2x^2 is 00. The inequality −5<1−2y3≤3-5 < \frac{1 - 2y}{3} \leq 3 simplifies to −4≤y<8-4 \leq y < 8. Since yy is an integer, its maximum value is 77. Therefore, the minimum possible value of x2−yx^2 - y is 0−7=−70 - 7 = -7.

Adım Adım Çözüm

1
Solve the absolute value inequality ∣4−3x∣≤13|4 - 3x| \leq 13 for xx.
−13≤4−3x≤13  ⟹  −17≤−3x≤9  ⟹  173≥x≥−3  ⟹  −3≤x≤173-13 \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 ∣u∣≤k|u| \leq k expands to −k≤u≤k-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<1−2y3≤3-5 < \frac{1 - 2y}{3} \leq 3 for yy.
−15<1−2y≤9  ⟹  −16<−2y≤8  ⟹  8>y≥−4  ⟹  −4≤y<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 x2−yx^2 - y.
Minimum (x2−y)=Minimum (x2)−Maximum (y)=0−7=−7\text{Minimum } (x^2 - y) = \text{Minimum } (x^2) - \text{Maximum } (y) = 0 - 7 = -7.
To minimize a difference A−BA - 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 −3∣x−2∣+4>−11-3|x - 2| + 4 > -11, which of the following inequalities represents all possible real values of xx?

Cevabı ve açıklamayı göster

Cevap: −3<x<7-3 < x < 7

Cevap

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

Adım Adım Çözüm

1
Subtract 4 from both sides of the inequality
−3∣x−2∣>−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
∣x−2∣<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<x−2<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 ∣2x−1∣≤5−x|2x - 1| \le 5 - x? Select all that apply.

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

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 −(5−x)≤2x−1≤5−x-(5 - x) \le 2x - 1 \le 5 - x yields the solution range −4≤x≤2-4 \le x \le 2. The candidate values −4-4, −1-1, and 11 all lie within this range, making them valid solutions.

Adım Adım Çözüm

1
Determine the non-negativity constraint for the right-hand side expression.
Since an absolute value ∣2x−1∣|2x - 1| must be non-negative, we must have 5−x≥05 - x \ge 0, which simplifies to x≤5x \le 5.
An absolute value cannot be less than a negative number.
2
Rewrite the absolute value inequality ∣2x−1∣≤5−x|2x - 1| \le 5 - x as a compound linear inequality.
−(5−x)≤2x−1≤5−x-(5 - x) \le 2x - 1 \le 5 - x, which expands to −5+x≤2x−1≤5−x-5 + x \le 2x - 1 \le 5 - x.
For any non-negative expression BB, ∣A∣≤B|A| \le B is logically equivalent to −B≤A≤B-B \le A \le B.
3
Solve the left-hand inequality −5+x≤2x−1-5 + x \le 2x - 1.
Subtracting xx from both sides gives −5≤x−1-5 \le x - 1. Adding 11 to both sides yields x≥−4x \ge -4.
Isolating xx establishes the lower bound of the solution set.
4
Solve the right-hand inequality 2x−1≤5−x2x - 1 \le 5 - x.
Adding xx to both sides gives 3x−1≤53x - 1 \le 5. Adding 11 yields 3x≤63x \le 6, so x≤2x \le 2.
Isolating xx establishes the upper bound of the solution set.
5
Intersect all constraints to find the valid domain for xx.
Combining x≥−4x \ge -4, x≤2x \le 2, and x≤5x \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+4∣≥11|3x + 4| \ge 11 and ∣x−1∣<6|x - 1| < 6, which of the following could be the value of xx? Select all that apply.

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: 33; 55

Cevap

The values 3 and 5 satisfy both inequalities.
Solving the first inequality ∣3x+4∣≥11|3x + 4| \ge 11 yields x≤−5x \le -5 or x≥73x \ge \frac{7}{3}. Solving the second inequality ∣x−1∣<6|x - 1| < 6 yields −5<x<7-5 < x < 7. Intersecting these two regions, the interval x≤−5x \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 73≤x<7\frac{7}{3} \le x < 7. Among the choices, 3 and 5 fall within this valid interval.

Adım Adım Çözüm

1
Solve the absolute value inequality ∣3x+4∣≥11|3x + 4| \ge 11.
x≤−5x \le -5 or x≥73x \ge \frac{7}{3}.
An absolute value inequality of the form ∣u∣≥k|u| \ge k (where k>0k > 0) splits into two separate inequalities: u≥ku \ge k or u≤−ku \le -k. Solving 3x+4≥113x + 4 \ge 11 gives 3x≥7  ⟹  x≥733x \ge 7 \implies x \ge \frac{7}{3}. Solving 3x+4≤−113x + 4 \le -11 gives 3x≤−15  ⟹  x≤−53x \le -15 \implies x \le -5.
2
Solve the absolute value inequality ∣x−1∣<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<x−1<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.
73≤x<7\frac{7}{3} \le x < 7.
The portion x≤−5x \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 x≥73x \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 73≈2.33\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 ∣3−2x∣≥5|3 - 2x| \ge 5 and 7−3x−2>−1\frac{7 - 3x}{-2} > -1, which of the following expresses all possible values of xx?

Cevabı ve açıklamayı göster

Cevap: x≥4x \ge 4

Cevap

The condition is satisfied by all values of xx such that x≥4x \ge 4.
Solving ∣3−2x∣≥5|3 - 2x| \ge 5 yields two separate intervals: x≤−1x \le -1 or x≥4x \ge 4. Solving 7−3x−2>−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 x≥4x \ge 4.

Adım Adım Çözüm

1
Solve the absolute value inequality ∣3−2x∣≥5|3 - 2x| \ge 5.
Splitting into two cases: 3−2x≥5  ⟹  −2x≥2  ⟹  x≤−13 - 2x \ge 5 \implies -2x \ge 2 \implies x \le -1, or 3−2x≤−5  ⟹  −2x≤−8  ⟹  x≥43 - 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 ∣u∣≥k|u| \ge k (for k>0k > 0) decouples into u≥ku \ge k or u≤−ku \le -k.
2
Solve the linear inequality 7−3x−2>−1\frac{7 - 3x}{-2} > -1.
Multiply both sides by −2-2 (reversing the inequality): 7−3x<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 x≥4x \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 ∣4x−5∣≤13|4x - 5| \le 13 and 2x−1−3≤−1\frac{2x - 1}{-3} \le -1, what is the sum of all possible values of xx?

Cevabı ve açıklamayı göster

Cevap: 9

Cevap

9
Solving the absolute value inequality ∣4x−5∣≤13|4x - 5| \le 13 yields −13≤4x−5≤13-13 \le 4x - 5 \le 13, which simplifies to −2≤x≤4.5-2 \le x \le 4.5. Next, solving 2x−1−3≤−1\frac{2x - 1}{-3} \le -1 requires multiplying both sides by −3-3 and reversing the inequality sign, giving 2x−1≥32x - 1 \ge 3, which simplifies to x≥2x \ge 2. Combining −2≤x≤4.5-2 \le x \le 4.5 and x≥2x \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 ∣4x−5∣≤13|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 ∣u∣≤k|u| \le k unfolds into the compound inequality −k≤u≤k-k \le u \le k.
2
Solve the linear inequality 2x−1−3≤−1\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 −2≤x≤4.5-2 \le x \le 4.5 and x≥2x \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
Linear Inequalities and Absolute Value Alıştırma Soruları — GRE General Test | Examkin