Estimate the area under the graph of $\displaystyle {f{{\left({x}\right)}}}=$$\displaystyle {x}^{{2}}+{8}{x}+{20}$ over the interval $\displaystyle {\left[{0},{8}\right]}$ using five approximating rectangles and right endpoints.

$\displaystyle {R}_{{n}}=$

Repeat the approximation using left endpoints.

$\displaystyle {L}_{{n}}=$

Report answers accurate to 4 places. Remember not to round too early in your calculations.