Question

Tính rõ ràng

1/20 + 3/5 =....

4/5 x 20/9 =...

4/5 - 5/8 =...

1/2 : 5/8

Answer 1

\(\dfrac{1}{20}+\dfrac{3}{5}=\dfrac{1}{20}+\dfrac{12}{20}=\dfrac{13}{20}\\ \dfrac{4}{5}\times\dfrac{20}{9}=\dfrac{4\times4\times5}{5\times9}=\dfrac{4\times4}{9}=\dfrac{16}{9}\\ \dfrac{4}{5}-\dfrac{5}{8}=\dfrac{32}{40}-\dfrac{2}{40}=\dfrac{7}{40}\\ \dfrac{1}{2}:\dfrac{5}{8}=\dfrac{1}{2}\times\dfrac{8}{5}=\dfrac{4\times2}{2\times5}=\dfrac{4}{5}\)

Answer 2

13/20

16/9

7/40

1/80

Answer 3

1/20 + 3/5= 1/20 + 12/20 = 13/20

4/5 x 20/9= 80/45=16/9

4/5:5/8=4/5x8/5=32/10= 16/5

1/2:5/8=1/2x8/5=8/10= 4/5

Answer 4

no bé ơi