Linear and Quadratic Inequalities

27 soru

Soru 21Soru

Find the largest integer value of xx that satisfies the linear inequality 2x53x+14\frac{2x - 5}{3} \le \frac{x + 1}{4}.

Cevabı ve açıklamayı göster

Cevap: 4

Cevap

The largest integer value of xx satisfying the inequality is 4.
Multiplying the entire inequality by 12 yields 4(2x - 5) <= 3(x + 1). Expanding both sides produces 8x - 20 <= 3x + 3. Subtracting 3x and adding 20 gives 5x <= 23, which simplifies to x <= 4.6. The largest integer less than or equal to 4.6 is 4.

Adım Adım Çözüm

1
Clear the denominators by multiplying both sides by 12.
4(2x - 5) \le 3(x + 1)
Multiplying by a positive number preserves the inequality direction while clearing fractions.
2
Expand both sides of the inequality using the distributive property.
8x - 20 \le 3x + 3
Multiply 4 through (2x - 5) and 3 through (x + 1).
3
Isolate the variable terms on one side and constant terms on the other.
5x \le 23 \implies x \le 4.6
Subtract 3x from both sides and add 20 to both sides, then divide by 5.
4
Determine the maximum integer value satisfying the inequality boundary.
4
Since x must be less than or equal to 4.6, the greatest whole integer satisfying this condition is 4.

Anahtar Kavram

Solving linear inequalities with fractions and finding integer bounds
Soru 22Soru

Find the sum of all integer values of xx that satisfy both the linear inequality 2x132x - 1 \ge 3 and the quadratic inequality x25x140x^2 - 5x - 14 \le 0.

Cevabı ve açıklamayı göster

Cevap: 27

Cevap

The sum of all integer values of xx satisfying both inequalities is 2727.
Solving the linear inequality 2x132x - 1 \ge 3 yields x2x \ge 2. Solving the quadratic inequality x25x140x^2 - 5x - 14 \le 0 by factoring gives (x7)(x+2)0(x - 7)(x + 2) \le 0, which defines the interval 2x7-2 \le x \le 7. Taking the intersection of x2x \ge 2 and 2x7-2 \le x \le 7 gives 2x72 \le x \le 7. The integer values satisfying this range are 2,3,4,5,6,2, 3, 4, 5, 6, and 77, and their sum is 2727.

Adım Adım Çözüm

1
Solve the linear inequality
2x4    x22x \ge 4 \implies x \ge 2
Adding 1 to both sides and dividing by 2 isolates the variable xx.
2
Factor and solve the quadratic inequality
(x7)(x+2)0    2x7(x - 7)(x + 2) \le 0 \implies -2 \le x \le 7
The roots of the quadratic equation are x=7x = 7 and x=2x = -2. The parabola opens upward, so the expression is non-positive between the roots.
3
Determine the intersection of both solution sets
2x72 \le x \le 7
The values of xx must simultaneously satisfy x2x \ge 2 and 2x7-2 \le x \le 7.
4
List all integer solutions within the valid interval
x{2,3,4,5,6,7}x \in \{2, 3, 4, 5, 6, 7\}
These are all the whole numbers contained in the closed interval [2,7][2, 7].
5
Sum the integer solutions
2+3+4+5+6+7=272 + 3 + 4 + 5 + 6 + 7 = 27
Summing the identified integer values yields the final required numerical answer.

Anahtar Kavram

Linear and Quadratic Inequalities
Tahmini Süre:1m 30s
Soru 23Soru

Find the set of real values of xx that satisfies the inequality 52x3x5\frac{5 - 2x}{3} \ge x - 5.

Cevabı ve açıklamayı göster

Cevap: x4x \le 4

Cevap

The set of real values satisfying the inequality is x4x \le 4.
Multiplying through by 33 yields 52x3x155 - 2x \ge 3x - 15. Rearranging terms gives 5x20-5x \ge -20. Dividing both sides by 5-5 requires flipping the inequality sign from \ge to \le, giving x4x \le 4.

Adım Adım Çözüm

1
Multiply both sides of the inequality by 3 to clear the fraction.
52x3(x5)5 - 2x \ge 3(x - 5)
Eliminating the denominator simplifies the algebraic expression.
2
Expand the right-hand side and collect terms containing xx on one side and constants on the other.
52x3x15    2x3x155    5x205 - 2x \ge 3x - 15 \implies -2x - 3x \ge -15 - 5 \implies -5x \ge -20
Group like terms to isolate the variable xx.
3
Divide both sides by 5-5 and reverse the inequality sign.
x205    x4x \le \frac{-20}{-5} \implies x \le 4
Dividing or multiplying an inequality by a negative number reverses the direction of the inequality sign.

Anahtar Kavram

Solving linear inequalities involving negative coefficient division
Soru 24Soru

Which of the following is the set of real values of xx that satisfies the inequality 3x42x+53\frac{3 - x}{4} \le \frac{2x + 5}{3}?

Cevabı ve açıklamayı göster

Cevap: x1x \ge -1

Cevap

The set of real values of xx that satisfies the inequality is x1x \ge -1.
Multiplying through by 12 gives 93x8x+209 - 3x \le 8x + 20. Grouping terms results in 11x11-11x \le 11. Dividing by 11-11 requires reversing the inequality sign from \le to \ge, giving the solution x1x \ge -1.

Adım Adım Çözüm

1
Clear the denominators by multiplying both sides of the inequality by the lowest common multiple, 12.
3(3x)4(2x+5)3(3 - x) \le 4(2x + 5)
Eliminating fractions simplifies the algebraic expression.
2
Expand both sides by distributing the multipliers.
93x8x+209 - 3x \le 8x + 20
Prepares terms for grouping variables on one side and constants on the other.
3
Collect all terms containing xx on the left side and constant terms on the right side.
3x8x209    11x11-3x - 8x \le 20 - 9 \implies -11x \le 11
Isolates the linear variable term.
4
Divide both sides by 11-11 and flip the inequality sign.
x1x \ge -1
Dividing or multiplying an inequality by a negative number reverses the direction of the inequality sign.

Anahtar Kavram

Linear Inequalities and Reversing Inequality Sign on Division by Negative Numbers
Soru 25Soru

Determine the smallest integer value of xx that satisfies the compound inequality 3<2x5113 < 2x - 5 \le 11.

Cevabı ve açıklamayı göster

Cevap: 5

Cevap

The smallest integer value of xx that satisfies the inequality is 5.
Adding 5 across the compound inequality 3<2x5113 < 2x - 5 \le 11 gives 8<2x168 < 2x \le 16. Dividing by 2 yields 4<x84 < x \le 8. The integer values satisfying this range are 5, 6, 7, and 8. Therefore, the smallest integer solution is 5.

Adım Adım Çözüm

1
Add 5 to all parts of the compound inequality
8 < 2x <= 16
Isolates the variable term in the middle segment.
2
Divide all parts of the compound inequality by 2
4 < x <= 8
Solves for x without changing inequality signs since 2 is positive.
3
Identify integer solutions within the range (4, 8]
x in {5, 6, 7, 8}
Since the inequality at 4 is strict (<), 4 is excluded, but 8 is included (<=).
4
Find the minimum integer value in the solution set
5
5 is the smallest integer strictly greater than 4.

Anahtar Kavram

Solving Compound Linear Inequalities
Soru 26Soru

Which of the following represents the solution set of real values of xx satisfying the inequality 4(1x)3(x+6)4(1 - x) \le 3(x + 6)?

Cevabı ve açıklamayı göster

Cevap: x2x \ge -2

Cevap

The set of real values satisfying the inequality is x2x \ge -2.
Expanding the given inequality yields 44x3x+184 - 4x \le 3x + 18. Subtracting 3x3x and 44 from both sides gives 7x14-7x \le 14. When dividing both sides by 7-7, the inequality sign must reverse direction, yielding x2x \ge -2.

Adım Adım Çözüm

1
Expand both sides of the inequality
44x3x+184 - 4x \le 3x + 18
Remove brackets to group like terms.
2
Rearrange terms by moving variable terms to the left side and constant terms to the right side
4x3x184    7x14-4x - 3x \le 18 - 4 \implies -7x \le 14
Isolate the term containing the variable xx.
3
Divide both sides by 7-7 and reverse the inequality sign
x2x \ge -2
Dividing or multiplying an inequality by a negative number flips the direction of the inequality symbol.

Anahtar Kavram

Solving linear inequalities involving bracket expansion and division by negative numbers
Soru 27Soru

How many integer values of xx satisfy the quadratic inequality 2x27x402x^2 - 7x - 4 \le 0?

Cevabı ve açıklamayı göster

Cevap: 5

Cevap

There are 5 integer values of x that satisfy the inequality.
Solving the quadratic inequality yields 12x4-\frac{1}{2} \le x \le 4. The integer solutions within this interval are 0,1,2,3,0, 1, 2, 3, and 44. Counting them gives a total of 55 valid integer values.

Adım Adım Çözüm

1
Factor the quadratic expression.
(2x+1)(x4)0(2x + 1)(x - 4) \le 0
Factoring allows determination of the critical boundary points.
2
Find the critical values (roots of the equation).
x=12x = -\frac{1}{2} and x=4x = 4
The roots divide the number line into test intervals.
3
Determine the solution set of the inequality.
12x4-\frac{1}{2} \le x \le 4
Since the quadratic coefficient is positive, the quadratic expression is non-positive between its roots.
4
List and count the integers within the range.
The integers are 0,1,2,3,40, 1, 2, 3, 4, making a total of 55 integers.
Counting only whole numbers in the closed interval [0.5,4][ -0.5, 4 ].

Anahtar Kavram

Quadratic Inequalities and Integer Solution Counting
ÖncekiSayfa 2 / 2
Linear and Quadratic Inequalities Alıştırma Soruları — JAMB UTME — Sayfa 2 | Examkin