Question

Tính bằng cách thuận tiện nhất:

\(\dfrac{2}{5}\) *\(\dfrac{4}{7}\)+\(\dfrac{3}{5}\)*\(\dfrac{4}{7}\)

Answer 1

\(\dfrac{4}{7}x\left(\dfrac{2}{5}+\dfrac{3}{5}\right)=\dfrac{4}{7}x1=\dfrac{4}{7}\)

Answer 2

2/5 x 4/7 + 3/5 x 4/7

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

= 1 x 4/7

= 4/7

Answer 3

    2/5 *4/7+3/5*4/7

=( 2/5 + 3/5 ) *4/7 

= 1 * 4/7

= 4/7

Answer 4

4/7x(2/5+3/5)=4/7x1=4/7x(2/5+3/5)=4/7x1=4/7

Answer 5

Băng 4/7 nha !

Answer 6

\(\dfrac{4}{7}\cdot\left(\dfrac{2}{5}+\dfrac{3}{5}\right)\)=\(\dfrac{4}{7}\cdot1\)=\(\dfrac{4}{7}\)