Question

Tìm x:

(2x+1)²=9

Answer 1

\(\left(2x+1\right)^2=9\)

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

⇔ \(\left[{}\begin{matrix}x=1\\x=-2\end{matrix}\right.\)

Answer 2

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

Answer 3

⇒[2x+1=32x+1=−3⇒[2x=22x=−4⇒[x=1x=−2⇒[2x+1=32x+1=−3⇒[2x=22x=−4⇒[x=1x=−2