$\text{a.|3x-5|=|x+2|}$
⇔\(\left[ \begin{array}{l}3x-5=x+2 \\3x-5=-x-2\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=\dfrac{7}{2} \\x=\dfrac{3}{4}\end{array} \right.\)
$\text{Vậy}$ $x∈ \begin{Bmatrix} \dfrac{7}{2};\dfrac{3}{4} \end{Bmatrix}$
$b.3x-2x=-7-5$
$⇔x=-12$
$\text{Vậy x=-12}$
$c.|-2x-5|=|3-x|$
⇔\(\left[ \begin{array}{l}-2x-5=3-x\\-2x-5=x-3\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=8\\x=\dfrac{-2}{3}\end{array} \right.\)
$\text{ Vậy}$ $x∈ \begin{Bmatrix} 8 ;\dfrac{-2}{3} \end{Bmatrix}$