Question

Answer 1

\(\dfrac{3}{13}+\dfrac{-3}{7}+\dfrac{10}{13}+\dfrac{-4}{7}\\ =\left(\dfrac{3}{13}+\dfrac{10}{13}\right)+\left(\dfrac{-3}{7}+\dfrac{-4}{7}\right)\\ =\dfrac{13}{13}+\dfrac{-7}{7}\\ =1+\left(-1\right)\\ =0\)

Answer 2

31/3+−3/7+10/13+−4/7

=(31/3+10/13)+(−3/7+−4/7)

=13/13+−7/7

=1+(−1)

=0