Question

Difficulty: EasyLinear Inequalities in One Variable

Which of the following inequalities is equivalent to 3(x4)<15-3(x - 4) < 15?

  1. x>1x > -1Answer
  2. B
    x<1x < -1
  3. C
    x>9x > -9
  4. D
    x<9x < -9

Answer

The inequality x>1x > -1
The correct answer is obtained by dividing both sides of the inequality 3(x4)<15-3(x - 4) < 15 by 3-3, which reverses the inequality symbol to yield x4>5x - 4 > -5. Adding 44 to both sides isolates the variable, resulting in x>1x > -1. Alternatively, distributing the 3-3 first yields 3x+12<15-3x + 12 < 15, which simplifies to 3x<3-3x < 3, and dividing by 3-3 with a sign flip yields x>1x > -1.

Step-by-Step Solution

1
Divide both sides of the inequality 3(x4)<15-3(x - 4) < 15 by 3-3.
x4>5x - 4 > -5
Dividing an inequality by a negative number reverses the direction of the inequality symbol.
2
Add 44 to both sides of the inequality to isolate xx.
x>1x > -1
Adding a constant to both sides preserves the inequality and isolates the variable xx.

Key Concept

Solving linear inequalities in one variable involving distribution and negative coefficients.
Rate this question