Question

Difficulty: MediumLinear Inequalities in One Variable

Which of the following represents all possible values of xx that satisfy the inequality 2(x4)+9>2x+5-2(x - 4) + 9 > 2x + 5?

  1. x<3x < 3Answer
  2. B
    x>3x > 3
  3. C
    x<1x < -1
  4. D
    x<2x < 2

Answer

x<3x < 3
Expanding the inequality by distributing 2-2 yields 2x+8+9>2x+5-2x + 8 + 9 > 2x + 5, which simplifies to 2x+17>2x+5-2x + 17 > 2x + 5. Subtracting 2x2x and 1717 from both sides isolates the variable terms, giving 4x>12-4x > -12. Dividing both sides by the negative coefficient 4-4 and reversing the inequality sign results in the solution set representing all values of xx less than 33.

Step-by-Step Solution

1
Distribute the coefficient 2-2 to the terms inside the parentheses on the left side of the inequality.
2x+8+9>2x+5-2x + 8 + 9 > 2x + 5
Applying the distributive property removes the parentheses so like terms can be combined.
2
Combine the constant terms on the left side.
2x+17>2x+5-2x + 17 > 2x + 5
Simplifying the constant terms makes it easier to isolate the variable.
3
Subtract 2x2x and 1717 from both sides of the inequality.
4x>12-4x > -12
This groups all terms containing the variable on the left side and all constant terms on the right side.
4
Divide both sides by 4-4 and reverse the inequality sign.
x<3x < 3
Dividing both sides of an inequality by a negative number requires reversing the direction of the inequality sign.

Key Concept

To solve a multi-step linear inequality, apply the distributive property, combine like terms, isolate the variable, and reverse the inequality sign when multiplying or dividing both sides by a negative number.
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