a) ${ (-x+5)(3-x)=0}$
⇒ \(\left[ \begin{array}{l}-x+5=0\\3-x=0\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}-x=-5\\x=3\end{array} \right.\)
⇒ ${\left[ \begin{array}{l}x=5\\x=3\end{array} \right.}$
$\text {Vậy x ∈ {3;5}}$
b) ${ x(2+x)(7-x)=0}$
⇒ \(\left[ \begin{array}{l}x=0\\2+x=0\\7-x=0\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=0\\x=-2\\x=7\end{array} \right.\)
$\text {Vậy x ∈ {0;-2;7}}$
d) ${ 17x+3.(-16x-37)=2x+43-4x}$
⇒ ${ 17x-48x-111=2x+43-4x}$
⇒ ${ 17x-48x-2x+4x=43+111}$
⇒ ${ -29x = 154}$
⇒ ${ x = \dfrac{-154}{29}}$
