bài 1.
a. $\frac{-3}{4}$ + $\frac{7}{4}$ = $\frac{-3+7}{4}$ = 1
b. $\frac{-3}{5}$ . $\frac{14}{19}$ + $\frac{-3}{5}$ . $\frac{5}{19}$ +3$\frac{3}{5}$ = $\frac{-3}{5}$ . ($\frac{14}{19}$ + $\frac{5}{19}$ ) +3$\frac{3}{5}$ = $\frac{-3}{5}$.1+3$\frac{3}{5}$ = $\frac{-3}{5}$ + 3$\frac{3}{5}$ = 3
c.(2$\frac{3}{5}$ -0,6) : 150% = (2$\frac{3}{5}$ - $\frac{3}{5}$ ) : $\frac{3}{2}$ = 2: $\frac{3}{2}$ = 2. $\frac{2}{3}$ = $\frac{4}{3}$
