Đáp án:
Giải thích các bước giải:
a, $17 - x = 7 - 6x$
$-x + 6x = 7 - 17$
$5x = -10$
$x =-2$
b, $-15 + 2x = 5x -21$
$5x - 2x = -15 + 21$
$3x = 6$
$x = 2$
c) $(2x - 4) . 3 = 0$
$2x - 4 = 0$
$2x = 4$
$x = 2$
d, $5 . (2x - 1) = -25$
$2x - 1 = -5$
$2x = -4$
$x = -2$
e,$ (2x - 4) . (x + 3) = 0$
\(\left[ \begin{array}{l}2x - 4=0\\x + 3=0\end{array} \right.\)
\(\left[ \begin{array}{l}x=2\\x=-3\end{array} \right.\)