Question

[Nguyễn Vũ I Vy]

1)tính hợp lý: \(\dfrac{-5}{13}\times\dfrac{4}{11}+\dfrac{-5}{13}\div\dfrac{11}{7}+\dfrac{18}{13}\)

Answer 1

[2611]

`[-5]/13xx4/11+[-5]/13:11/7+18/13`

`=[-5]/13xx4/11+[-5]/13xx7/11+18/13`

`=[-5]/13xx(4/11+7/11)+18/13`

`=[-5]/13xx11/11+18/13`

`=[-5]/13+18/13=13/13=1`

Answer 2

[Nhật Nguyễn]

$\frac{-5}{13}\times \frac{4}{11}+\frac{-5}{13}:\frac{11}{7}+\frac{18}{13}$

$=\frac{-5}{13}\times \frac{4}{11}+\frac{-5}{13}\times \frac{7}{11}+\frac{18}{13}$

$=\frac{-5}{13}\times (\frac{4}{11}+\frac{7}{11})+\frac{18}{13}$

$=\frac{-5}{13}\times \frac{11}{11}+\frac{18}{13}$

$=\frac{-5}{13}+\frac{18}{13}=\frac{13}{13}=1$