## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$$=P-2Pr+Pr^2$$
In order to find a polynomial that gives the amount after two years, we plug in 2 for t and multiply out the expression to obtain: $$P\left(1-r\right)^2 \\ P\left(r^2-2r+1\right) \\ =P-2Pr+Pr^2$$