Question

A = |x - 5| - |x +2|

Answer 1

\(A=\left|x-5\right|-\left|x+2\right|\)

TH1: \(x\ge5\)

\(\Rightarrow A=x-5-x-2=-7\)

TH2: \(5>x\ge-2\)

\(\Rightarrow A=5-x-x-2=3-2x\)

TH3: \(x< -2\)

\(A=x-5+x+2=2x-3\)

Answer 2

\(A=\left|x-5\right|-\left|x+2\right|\)

≥\(\left|x-5-x-2\right|\)

≥ 7

⇔\(\left(x-5\right)\left(x+2\right)\)≥0

⇔2 ≤x ≤5

Answer 3

Đề bài yêu cầu gì?