-0,6.x - $\frac{7}{3}$ = 5,4
⇔ -0,6.x = 5,4 + $\frac{7}{3}$
⇔ -0,6.x = $\frac{116}{15}$
⇔ x = $\frac{116}{15}$ ÷ (-0,6)
⇔ x = $\frac{-116}{9}$
2,8÷($\frac{1}{5}$-3.x)=1$\frac{2}{5}$
⇔ 2,8 ÷ ($\frac{1}{5}$-3.x) = $\frac{7}{5}$
⇔ $\frac{1}{5}$ - 3.x = 2,8 ÷ $\frac{7}{5}$
⇔ $\frac{1}{5}$ - 3.x = 2
⇔ 3.x = $\frac{1}{5}$ - 2
⇔ 3.x = -$\frac{9}{5}$
⇔ x = -$\frac{9}{5}$ ÷ 3
⇔ x = -$\frac{3}{5}$
Chúc bạn học tốt!