[tex]\bf (5x-4)^2=36\implies (5x-4)(5x-4)=36\impliedby using\ FOIL
\\\\\\
5^2x^2-40x+16=36\implies 25x^2-40x+16-36=0
\\\\\\
25x^2-40x-20=0\implies 5(5x^2-8x-4)=0
\\\\\\
5x^2-8x-4=0\implies (5x+2)(x-2)=0\implies
\begin{cases}
5x+2=0\\
5x=-2\\\\
x=\cfrac{-2}{5}\\
-----\\
x-2=0\\
x=2
\end{cases}[/tex]
