a,1$\frac{3}{5}$ +$\frac{5}{6}$ =$\frac{8}{5}$ +$\frac{5}{6}$ =$\frac{73}{30}$ 

b,2$\frac{3}{5}$ -1$\frac{2}{3}$  =$\frac{13}{5}$ -$\frac{5}{3}$ $\frac{14}{15}$ 

c,3$\frac{3}{7}$ +2$\frac{1}{2}$ =$\frac{24}{7}$ +$\frac{5}{2}$ =$\frac{83}{14}$ 

d,-2$\frac{1}{2}$ -3$\frac{1}{4}$ =$\frac{-5}{2}$ -$\frac{13}{4}$ =$\frac{-23}{4}$ 

ko hiểu j thì hỏi nhé