Question

Rút gọn biểu thức

\(\sqrt{x^2+4x+4}-\sqrt{x^2}\) với \(-2\le x\le0\)

Answer 1

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

Answer 2

\(\sqrt{x^2+4x+4}-\sqrt{x^2}=\sqrt{\left(x+2\right)^2}-\sqrt{x^2}=\left|x+2\right|-\left|x\right|=x+2+x=2x+2\)