(4x-2)(x+5)=0
⇒\(\left[ \begin{array}{l}4x-2=0\\x+5=0\end{array} \right.\)⇔ \(\left[ \begin{array}{l}4x=2\\x=-5\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x=2:4\\x=-5\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x=\frac{1}{2} \\x=-5\end{array} \right.\)