` 2/9 + (-5/7)= 14/63 + (-45/63) = -31/63`
`-13/5 + 7/6 = -78/30 + 35/30 = -43/30`
1/\(\dfrac{3}{5}+\dfrac{4}{3}=\dfrac{9}{15}+\dfrac{20}{15}=\dfrac{9+20}{15}=\dfrac{29}{15}\)
2/ \(\dfrac{7}{2}-\dfrac{5}{3}=\dfrac{21}{6}-\dfrac{10}{6}=\dfrac{21-10}{6}=\dfrac{11}{6}\)
3/ \(\dfrac{8}{7}-\dfrac{1}{2}=\dfrac{16}{14}-\dfrac{7}{14}=\dfrac{16-7}{14}=\dfrac{9}{14}\)
4/ \(\dfrac{9}{11}+\dfrac{-3}{5}=\dfrac{45}{55}+\dfrac{-33}{55}=\dfrac{45+\left(-33\right)}{55}=\dfrac{+\left(45-33\right)}{55}=\dfrac{12}{55}\)
5/ \(\dfrac{2}{9}+\dfrac{-5}{7}=\dfrac{14}{63}+\dfrac{-45}{63}=\dfrac{14+\left(-45\right)}{63}=\dfrac{-\left(45-14\right)}{63}=\dfrac{31}{63}\)
6/ \(-\dfrac{13}{5}+\dfrac{7}{6}=-\dfrac{78}{30}+\dfrac{35}{30}=\dfrac{-78+35}{30}=\dfrac{-\left(78-35\right)}{30}=-\dfrac{43}{30}\)
