Question

Difficulty: MediumLinear and Quadratic Inequalities

Find the set of real values of xx that satisfies the inequality 5−2x3≥x−5\frac{5 - 2x}{3} \ge x - 5.

  1. A
    x≥4x \ge 4
  2. x≤4x \le 4Answer
  3. C
    x≤−4x \le -4
  4. D
    x≥−4x \ge -4

Answer

The set of real values satisfying the inequality is x≤4x \le 4.
Multiplying through by 33 yields 5−2x≥3x−155 - 2x \ge 3x - 15. Rearranging terms gives −5x≥−20-5x \ge -20. Dividing both sides by −5-5 requires flipping the inequality sign from ≥\ge to ≤\le, giving x≤4x \le 4.

Step-by-Step Solution

1
Multiply both sides of the inequality by 3 to clear the fraction.
5−2x≥3(x−5)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.
5−2x≥3x−15  ⟹  −2x−3x≥−15−5  ⟹  −5x≥−205 - 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.
x≤−20−5  ⟹  x≤4x \le \frac{-20}{-5} \implies x \le 4
Dividing or multiplying an inequality by a negative number reverses the direction of the inequality sign.

Key Concept

Solving linear inequalities involving negative coefficient division
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