Bài 1: Trang 153 - sách giáo khoa (SGK) toán tiếng Anh lớp 4calculate:Tính:a)...

Cách làm:

a) $\frac{3}{5}+\frac{11}{20}$= $\frac{12}{20}+\frac{11}{20}$=$\frac{12+11}{20}$=$\frac{23}{20}$

b) $\frac{5}{8}-\frac{4}{9}$= $\frac{45}{72}-\frac{32}{72}$=$\frac{45+32}{72}$=$\frac{13}{72}$

c) $\frac{9}{16}\times \frac{4}{3}$= $\frac{9\times4}{16\times 3}$=$\frac{36}{48}$=$\frac{3}{4}$

d) $\frac{4}{7}:\frac{8}{11}$= $\frac{4\times 11}{7\times 8}$=$\frac{44}{56}$=$\frac{11}{14}$

e) $\frac{3}{5}+\frac{4}{5}:\frac{2}{5}$= $\frac{3}{5}+\frac{4\times 5}{5\times 2}$=$\frac{3}{5}+\frac{20}{10}$=$\frac{6}{10}+\frac{20}{10}$=$\frac{26}{10}$=$\frac{13}{5}$

Trả lời:
a) $\frac{3}{5}+\frac{11}{20}= \frac{23}{20}$
b) $\frac{5}{8}-\frac{4}{9}= \frac{13}{72}$
c) $\frac{9}{16}\times \frac{4}{3}= \frac{3}{4}$
d) $\frac{4}{7}:\frac{8}{11}= \frac{11}{14}$
e) $\frac{3}{5}+\frac{4}{5}:\frac{2}{5}= \frac{13}{5}$