Question

\(\dfrac{-3}{5}+\dfrac{7}{21}+\dfrac{-4}{5}+\dfrac{7}{5}\)

\(\dfrac{-3}{17}+(\dfrac{2}{3}+\dfrac{3}{17})\)

Answer 1

`(-3)/5+7/21+(-4)/5+7/5`

`=(-3)/5+(-4)/5+7/5+7/21`

`=0+7/21=7/21`

`(-3)/17+(2/3+3/17)`

`=(-3)/17+3/17+2/3`

`=0+2/3=2/3`

Answer 2

\(-\dfrac{3}{5}+\dfrac{7}{21}+-\dfrac{4}{5}+\dfrac{7}{5}\)

\(=\left(\dfrac{-3-4+7}{5}\right)+\dfrac{7}{21}=0+\dfrac{7}{21}=\dfrac{7}{21}\)

\(-\dfrac{3}{17}+\left(\dfrac{2}{3}+\dfrac{3}{17}\right)=\left(-\dfrac{3}{17}+\dfrac{3}{17}\right)+\dfrac{2}{3}=0+\dfrac{2}{3}=\dfrac{2}{3}\)