Question

Tìm x, biết: 
a) (x+2)²-(x-2)(x+2)=0

Answer 1

\(\left(x+2\right)^2-\left(x-2\right)\left(x+2\right)=0\)

\(\Leftrightarrow\left(x+2\right)\left(x+2-x+2\right)=0\)

\(\Leftrightarrow4\left(x+2\right)=0\)

\(\Leftrightarrow x+2=0\)

\(\Leftrightarrow x=-2\)

Answer 2

a) \(\Leftrightarrow\left(x+2\right)\left(x+2-x+2\right)=0\)

    \(\Leftrightarrow4\left(x+2\right)=0\)

    \(\Leftrightarrow x+2=0\)

    \(\Leftrightarrow x=-2\)