a, x - $\frac{5}{8}$x = $\frac{15}{2}$
( 1 - $\frac{5}{8}$ )x = $\frac{15}{2}$
$\frac{3}{8}$x =$\frac{15}{2}$
x = $\frac{15}{2}$ : $\frac{3}{8}$ = 20
b, 5,5x = $\frac{13}{15}$
$\frac{11}{2}$x = $\frac{13}{15}$
x = $\frac{13}{15}$ : $\frac{11}{2}$ = $\frac{26}{165}$
c, x : 4$\frac{1}{4}$ = -3,2
x : $\frac{17}{4}$ = $\frac{-16}{5}$
x = $\frac{-16}{5}$ . $\frac{17}{4}$ =$\frac{-51}{5}$
CHO MÌNH CTLHN NHA.
