Question

Tính hợp lí -2/5 × 4/7 + -3/5 × 2/7 + -3/5

Answer 1

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

= \(\dfrac{-8}{35}+\dfrac{-6}{35}+\dfrac{-3}{5}\) 

=\(\dfrac{-8-6-21}{35}\) 

=\(\dfrac{-35}{35}\) 

=-1

Answer 2

`(-2)/5.4/7+(-3)/5.2/7+(-3)/5`

`=(-8)/3 +(-6)/35+(-3)/5`

`=(-8)-6-21/35`

`=(-35)/35`

`=(-1)`

`@Nae`

Answer 3

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

`=(-8)/3 +(-6)/35+(-3)/5`

`=(-8)-6-21/35`

`=(-35)/35`

`=(-1)`

`@Nae`