Question

Difficulty: MediumLinear Inequalities in One Variable

For which values of xx is the inequality 4(2x5)3x+9-4(2x - 5) \geq 3x + 9 true?

  1. A
    x1x \geq 1
  2. B
    x1x \leq -1
  3. x1x \leq 1Answer
  4. D
    x2911x \leq -\frac{29}{11}

Answer

The inequality is true for all values of xx such that xx is less than or equal to 11.
The correct inequality representing the solution set is the one that shows the variable is less than or equal to one.

Step-by-Step Solution

1
Distribute the factor of 4-4 to the terms inside the parentheses on the left side of the inequality.
8x+203x+9-8x + 20 \geq 3x + 9
Applying the distributive property gives 4×2x=8x-4 \times 2x = -8x and 4×5=20-4 \times -5 = 20.
2
Subtract 3x3x from both sides of the inequality to collect all terms with the variable xx on the left side.
11x+209-11x + 20 \geq 9
Grouping the variable terms helps isolate the variable.
3
Subtract 2020 from both sides of the inequality to isolate the variable term.
11x11-11x \geq -11
Subtracting twenty from both sides moves the constant terms to the right side of the inequality.
4
Divide both sides by 11-11 and reverse the direction of the inequality sign.
x1x \leq 1
Dividing or multiplying an inequality by a negative number requires flipping the inequality symbol.

Key Concept

Linear Inequalities in One Variable
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