Question

\(\dfrac{-5}{7}\times\dfrac{3}{13}-\dfrac{5}{7}\times\dfrac{10}{13}+1\dfrac{5}{7}\)

Answer 1

Lời giải:

$\frac{-5}{7}\times \frac{3}{13}-\frac{5}{7}\times \frac{10}{13}+1\frac{5}{7}$

$=\frac{5}{7}\times \frac{-3}{13}-\frac{5}{7}\times \frac{10}{13}+1+\frac{5}{7}$

$=\frac{5}{7}\times (\frac{-3}{13}-\frac{10}{13}+1)+1$

$=\frac{5}{7}\times (\frac{-13}{13}+1)+1$

$=\frac{5}{7}\times 0+1=1$