Question

Tính :

2/5 + 4/7

3/5 + 4/3 

( Chi tiết ra giùm vs ạ )

Answer 1

\(\dfrac{2}{5}+\dfrac{4}{7}=\dfrac{14}{35}+\dfrac{20}{35}=\dfrac{34}{35}\)

\(\dfrac{3}{5}+\dfrac{4}{3}=\dfrac{9}{15}+\dfrac{20}{15}=\dfrac{29}{15}\)

Answer 2

\(\dfrac{14}{35}+\dfrac{20}{35}=\dfrac{34}{35}\)

\(\dfrac{9}{15}+\dfrac{20}{15}=\dfrac{29}{15}\)

Answer 3

Answer 4

a, \(\dfrac{2}{5}\) + \(\dfrac{4}{7}\) = \(\dfrac{2x7}{5x7}\) + \(\dfrac{4x5}{7x5}\) = \(\dfrac{14}{35}\) + \(\dfrac{20}{35}\) = \(\dfrac{34}{35}\)
b, \(\dfrac{3}{5}\) + \(\dfrac{4}{3}\) = \(\dfrac{3x3}{5x3}\) + \(\dfrac{4x5}{3x5}\) = \(\dfrac{9}{15}\) + \(\dfrac{20}{15}\) = \(\dfrac{29}{15}\)