Đáp án: $S_{}$ = {$-2 ; \frac{8}{7}$}
Giải thích các bước giải:
$|7-2x|=|1-5x|_{}$
⇔ \(\left[ \begin{array}{l}7-2x=1-5x\\7-2x=-(1-5x)\end{array} \right.\)
⇔ \(\left[ \begin{array}{l}7-2x=1-5x\\7-2x=-1+5x\end{array} \right.\)
⇔ \(\left[ \begin{array}{l}-2x+5x=1-7\\-2x-5x=-1-7\end{array} \right.\)
⇔ \(\left[ \begin{array}{l}3x=-6\\-7x=-8\end{array} \right.\)
⇔ \(\left[ \begin{array}{l}x=(-6):3\\x=(-8):(-7)\end{array} \right.\)
⇔ \(\left[ \begin{array}{l}x=-2\\x=\frac{8}{7}\end{array} \right.\)
Vậy: $S_{}$ = {$-2 ; \frac{8}{7}$}
