Đáp án: Bên dưới.
Giải thích các bước giải:
a) $3(5-2x) -4(x+2) =5x-18_{}$
$15-6x-(4x+8)=5x-18_{}$
$15-6x-4x-8=5x-18_{}$
$-6x-4x-5x=-18-15+8_{}$
$-15x=-25_{}$
$x=_{}$ $\frac{5}{3}$
b) $(x+7) . (1-2x) =0_{}$
\(\left[ \begin{array}{l}x+7=0\\1-2x=0\end{array} \right.\)
\(\left[ \begin{array}{l}x=-7\\-2x=-1\end{array} \right.\)
\(\left[ \begin{array}{l}x=-7\\x=\frac{1}{2} \end{array} \right.\)
c) $15x+8=13x+10_{}$
$15x-13x=10-8_{}$
$2x= 2{}$
$x= 1_{}$
