Chapter 3 - Equations and Problem Solving - 3.1 - Solving First-Degree Equations - Problem Set 3.1 - Page 100: 75

$500=P$

We start with the given equation: $i=Prt$ We plug in the values for $i$, $t$, and $r$: $200=(0.08)(5)P$ We simplify the right side of the equation by multiplying: $200=0.4P$ We are trying to get $P$ by itself. In order to do so, we must divide by $0.4$ on each side of the equation and then simplify: $$\frac{200}{0.4}=\frac{0.4P}{0.4}$$$$500=P$$