c) `\frac{-3}{7}.\frac{5}{11}+\frac{-5}{14}.\frac{5}{11}`
`=\frac{5}{11}.(\frac{-3}{7}+\frac{-5}{14})`
`=\frac{5}{11}.\frac{-11}{14}`
`=\frac{-5}{14}`
d) `(\frac{-3}{4}+\frac{2}{5}):\frac{3}{7}+(\frac{3}{5}+\frac{-1}{4}):\frac{3}{7}`
`=(\frac{-3}{4}+\frac{2}{5}+\frac{3}{5}+\frac{-1}{4}):\frac{3}{7}`
`=(-1+1):\frac{3}{7}`
`=0:\frac{3}{7}`
`=0`
