Toán Lớp 5: Tính : a , $\frac{3}{5}$ + $\frac{5}{7}$ ==-.. $\frac{3}{4}$ + $\frac{5}{6}$ ==–.. $\frac{3}{4}$ + 2$\f

Toán Lớp 5: Tính :
a , $\frac{3}{5}$ + $\frac{5}{7}$ =………………
$\frac{3}{4}$ + $\frac{5}{6}$ =………………….
$\frac{3}{4}$ + 2$\frac{5}{7}$ =…………………
1$\frac{3}{4}$ + 7$\frac{5}{6}$ =………………..
b , $\frac{19}{12}$ – $\frac{3}{4}$ =…………….
$\frac{19}{12}$ – $\frac{5}{6}$ =………………..
1$\frac{11}{35}$ – $\frac{5}{7}$ =……………….
7$\frac{19}{12}$ – 4$\frac{5}{6}$ =………………