Question

Tìm x, biết

(x+6)² - (x-6)(x+6)= 0

Answer 1

\(\left(x+6\right)^2-\left(x-6\right)\left(x+6\right)=0\)

\(\Leftrightarrow\left(x+6\right)\left(x+6-6\right)=0\)

\(\Leftrightarrow x\left(x+6\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x+6=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-6\end{matrix}\right.\)

Vậy..

Answer 2

\(\left(x+6\right)^2-\left(x-6\right)\left(x+6\right)=0\)

\(\Leftrightarrow\left(x+6\right)\left(x+6-x-6\right)=0\)

\(\Leftrightarrow\left(x+6\right).0=0\)

\(\Leftrightarrow x+6=0\)

\(\Leftrightarrow x=-6\)

Vậy ................................