a) $\frac{3}{2}$.X+$\frac{1}{5}$ =70%
$\frac{3}{2}$.X = $\frac{7}{10}$ - $\frac{1}{5}$
$\frac{3}{2}$.X = $\frac{1}{2}$
X = $\frac{1}{2}$ : $\frac{3}{2}$
X = $\frac{1}{3}$
Vậy X = $\frac{1}{3}$
b) 2$\frac{2}{3}$.X+8$\frac{2}{3}$ =3$\frac{1}{2}$
2+8+$\frac{2}{3}$(X+1)= $\frac{7}{2}$
$\frac{2}{3}$(X+1)= $\frac{7}{2}$ -10
$\frac{7}{2}$(x+1)= $\frac{-13}{2}$
x+1 = $\frac{-13}{7}$
x = $\frac{-20}{7}$
Vậy x = $\frac{-20}{7}$
c) X:$\frac{8}{11}$ =$\frac{11}{3}$
X = $\frac{11}{3}$ . $\frac{8}{11}$
X = $\frac{8}{3}$
Vậy X = $\frac{8}{3}$
d) $\frac{3}{4}$ .X+ $\frac{1}{5}$ .X = $\frac{1}{6}$
X.($\frac{3}{4}$ +$\frac{1}{5}$) = $\frac{1}{6}$
X. $\frac{19}{20}$ = $\frac{1}{6}$
X = $\frac{10}{57}$
Vậy ...
g) giống bài b