\(\left(\dfrac{-1}{2}\right)^3+\left(\dfrac{-1}{2}\right)^2+\left(\dfrac{-1}{2}\right)^1+\left(\dfrac{-1}{2}\right)^0\)
= \(\left(\dfrac{-1}{8}\right)+\dfrac{1}{4}+\left(\dfrac{-1}{2}\right)+1\)
= \(\left(\dfrac{-1}{8}\right)+\dfrac{2}{8}+\left(\dfrac{-4}{8}\right)+\dfrac{8}{8}\)
= \(\dfrac{\left(-1\right)+2+\left(-4\right)+8}{8}\)
= \(\dfrac{5}{8}\)