a) x + $\frac{9}{-5}$ = $\frac{-7}{8}$
x = $\frac{-7}{8}$ - $\frac{9}{-5}$
x =$\frac{37}{40}$
b) 8% . x + $\frac{6}{25}$ . x = $\frac{8}{11}$
$\frac{8}{100}$ . x + $\frac{6}{25}$ . x = $\frac{8}{11}$
( $\frac{8}{100}$ + $\frac{6}{25}$ ) . x = $\frac{8}{11}$
$\frac{8}{25}$ . x = $\frac{8}{11}$
x = $\frac{8}{11}$ : $\frac{8}{25}$
x = $\frac{25}{11}$
c) 2 . | x - $\frac{1}{2}$ | = 9
| x - $\frac{1}{2}$ | = 9 : 2
| x - $\frac{1}{2}$ | = $\frac{9}{2}$
=> \(\left[ \begin{array}{l}x - \frac{1}{2} = \frac{9}{2} \\x - \frac{1}{2} = - \frac{9}{2} \end{array} \right.\)
=>\(\left[ \begin{array}{l}x = \frac{9}{2} + \frac{1}{2} \\x = - \frac{9}{2} + \frac{1}{2} \end{array} \right.\)
=> \(\left[ \begin{array}{l}x = 5 \\x = 4 \end{array} \right.\)
Xin hay nhất nha bạn :)
