Question

(2x+1)^2-16=9

Answer 1

\(\left(2x+1\right)^2=25=5^2=\left(-5\right)^2\\ \left[{}\begin{matrix}2x+1=5\\2x+1=-5\end{matrix}\right.\left[{}\begin{matrix}2x=6\\2x=-4\end{matrix}\right.\left[{}\begin{matrix}x=3\\x=-2\end{matrix}\right.\)

Answer 2

\(\Leftrightarrow\left[{}\begin{matrix}2x+1=5\\2x+1=-5\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-3\end{matrix}\right.\)