Question

Tìm x: |x+2| + |x-2|= 3

Answer 1

\(\left|x+2\right|+\left|x-2\right|=3\)

TH1:\(x< -2\)

Pt \(\Leftrightarrow-\left(x+2\right)-\left(x-2\right)=3\)

\(\Leftrightarrow x=-\dfrac{3}{2}\left(ktm\right)\)

TH2:\(-2\le x\le2\)

Pt \(\Leftrightarrow x+2-\left(x-2\right)=3\Leftrightarrow4=3\) (vô lí)

TH3:\(>2\)

Pt \(\Leftrightarrow x+2+x-2=3\Leftrightarrow x=\dfrac{3}{2}\left(ktm\right)\)

Vậy pt vô nghiệm