Solve |x+1| ≤ 7-x: Absolute Value Inequality Analysis

Question

Given:

x+17x \left|x + 1\right| \leq 7 - x

Which of the following statements is necessarily true?

Step-by-Step Solution

To solve x+17x \left|x + 1\right| \leq 7 - x , we split it into two cases due to the absolute value:

1. x+17x x + 1 \leq 7 - x

2. x17x -x - 1 \leq 7 - x

Solving case 1:

x+17xx+x712x6x3 x + 1 \leq 7 - x \Rightarrow x + x \leq 7 - 1 \Rightarrow 2x \leq 6 \Rightarrow x \leq 3

Solving case 2:

x17x17 -x - 1 \leq 7 - x \Rightarrow -1 \leq 7 (always true)

Both parts confirm that x3 x \leq 3 is the only true inequality.

Answer

x3 x \leq 3