a: =2/3+1/5*10/7
=2/3+2/7
=14/21+6/21=20/21
b: \(=\dfrac{1}{2}\cdot\dfrac{-3+2}{4}=\dfrac{1}{2}\cdot\dfrac{-1}{4}=\dfrac{-1}{8}\)
c: \(=\dfrac{3}{4}+\dfrac{9}{5}:\dfrac{3}{2}-1\)
=-1/4+9/5*2/3
=-1/4+18/15
=-1/4+6/5
=-5/20+24/20=19/20
d: \(=\dfrac{3}{2}\cdot\left(\dfrac{7}{3}-\dfrac{5}{3}\cdot4\right)\)
\(=\dfrac{7}{2}-\dfrac{5}{2}\cdot4=\dfrac{7}{2}-\dfrac{20}{2}=\dfrac{-13}{2}\)