Question

tìm x

(2x+1)²-(x-2)²=0

Answer 1

\(\left(2x+1\right)^2-\left(x-2\right)^2=0\)

\(\left(2x+1-x+2\right)\left(2x+1+x-2\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}2x+1-x+2=0\\2x+1+x-2=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x+3=0\\3x-1=0\end{matrix}\right.\)

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

Answer 2

Answer 3

\(\left(2x+1\right)^2-\left(x-2\right)^2=0\\ \Leftrightarrow\left(x+3\right)\left(3x-1\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x+3=0\\3x-1=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=-3\\x=\dfrac{1}{3}\end{matrix}\right.\)