Question

( 27 - x ) . ( x + 9) = 0

Answer 1

\(\Rightarrow\left[{}\begin{matrix}27-x=0\\x+9=0\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=27\\x=-9\end{matrix}\right.\)

Answer 2

\(\Leftrightarrow\left[{}\begin{matrix}x=27\\x=-9\end{matrix}\right.\)