(x+1/2)2=9 <=> (x+1/2)2=32 <=> x+1/2=3 => x=5/2 !!
\(\left(x+\frac{1}{2}\right)^2=9\)
\(\Rightarrow\orbr{\begin{cases}\left(x+\frac{1}{2}\right)^2=3^2\\\left(x+\frac{1}{2}\right)^2=\left(-3\right)^2\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x+\frac{1}{2}=3\\x+\frac{1}{2}=-3\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=3-\frac{1}{2}\\x=-3-\frac{1}{2}\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=\frac{5}{2}\\x=-\frac{7}{2}\end{cases}}\)
\(x+\frac{1}{2}=3hoac-3\)
\(x=3-\frac{1}{2}=\frac{5}{2}hoac-3-\frac{1}{2}=-\frac{7}{2}\)
(x+1/2)2=(+-3)2 => x+1/2 =-3 hoặc x+1/2=3 => x=-7/2 hoặc x=5/2