Question

Tinh thuận tiên 2/5+3/7+3/5+4/7

 

Answer 1

\(\dfrac{2}{5}+\dfrac{3}{7}+\dfrac{3}{5}+\dfrac{4}{7}\\ =\left(\dfrac{2}{5}+\dfrac{3}{5}\right)+\left(\dfrac{3}{7}+\dfrac{4}{7}\right)\\ =\dfrac{5}{5}+\dfrac{7}{7}\\ =1+1\\ =2.\)

Answer 2

`2/5+3/7+3/5+4/7`

`=(2/5+3/5)+(3/7+4/7)`

`=5/5+7/7`

`=1+1`

`=2`

Answer 3

` 2/5+3/7+3/5+4/7`

`= ( 2/5+3/5)+(3/7+4/7)`

`=    1 + 1 = 2`