`(a):(5)/(6)+(7)/(12)`
`=(10)/(12)+(7)/(12)`
`=(17)/(12)`
`(b):(9)/(16)-(3)/(8)`
`=(9)/(16)-(6)/(16)`
`=(3)/(16)`
`(c):(11)/(10)+(3)/(5):(2)/(3)`
`=(11)/(10)+(3)/(5)xx(3)/(2)`
`=(11)/(10)+(9)/(10)`
`=(20)/(10)=2`
a) \(\dfrac{5}{6}+\dfrac{7}{12}=\dfrac{10}{12}+\dfrac{7}{12}=\dfrac{10+7}{12}=\dfrac{17}{12}\)
b) \(\dfrac{9}{16}-\dfrac{3}{8}=\dfrac{9}{16}-\dfrac{6}{16}=\dfrac{9-6}{16}=\dfrac{3}{16}\)
c) \(\dfrac{11}{10}+\dfrac{3}{5}:\dfrac{2}{3}=\dfrac{11}{10}+\dfrac{3}{5}\cdot\dfrac{3}{2}=\dfrac{11}{10}+\dfrac{3\cdot3}{5\cdot2}=\dfrac{11}{10}+\dfrac{9}{10}=\dfrac{11+9}{10}=\dfrac{20}{10}=2\)