`(5x-2)^2-25=0`
`<=>(5x-2)^2-5^2=0`
`<=>(5x-2+5)(5x-2-5)=0`
`<=>(5x+3)(5x-7)=0`
`<=>[(x=-3/5),(x=7/5):}`
\(\left(5x-2\right)^2-25=0\\ \Leftrightarrow\left(5x-2-5\right)\left(5x-2+5\right)=0\\ \Leftrightarrow\left(5x-7\right)\left(5x+3\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{7}{5}\\x=\dfrac{-3}{5}\end{matrix}\right.\)
Vậy \(x\in\left\{\dfrac{7}{5};\dfrac{-3}{5}\right\}\) là nghiệm của pt.
Ta có: \(\left(5x-2\right)^2-25=0\)
\(\Leftrightarrow\left(5x-7\right)\left(5x+3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{7}{5}\\x=-\dfrac{3}{5}\end{matrix}\right.\)
