Chapter 1.2, Problem 100E

In the following exercises, given that ${\displaystyle {\int }_0^{1}xdx=\frac{1}{2}},{\displaystyle {\int }_0^1{x}^{2}dx=\frac{1}{3}}$ , and ${\displaystyle {\int }_0^1{x}^{3}dx=\frac{1}{4}}$ compute the integrals.

100. ${\displaystyle {\int }_0^1{\left(1-x\right)}^{2}dx}$