Question

TÌM X (X-3)(X+3)-(X-6)²=-9

Answer 1

\(\Rightarrow x^2-9-x^2+6x-9=-9\\ \Rightarrow6x=9\Rightarrow x=\dfrac{3}{2}\)

Answer 2

\(\left(x-3\right)\left(x+3\right)-\left(x-6\right)^2=-9\)

\(\Leftrightarrow x^2-9-x^2+12x-36=-9\)

\(\Leftrightarrow12x=36\Leftrightarrow x=3\)