Answer
$ P=\frac{A}{rT+1}$.
Work Step by Step
Multiply both sides of the given formula by $Pr$ to clear denominators.
$\Rightarrow PrT=Pr\left (\frac{A-P}{Pr}\right )$
Cancel common terms.
$\Rightarrow PrT=A-P$
Add $P$ to both sides.
$\Rightarrow PrT+P=A-P+P$
Factor out P on the left side and simplify.
$\Rightarrow P(rT+1)=A$
Divide both sides by $(rT+1)$.
$\Rightarrow \frac{P(rT+1)}{(rT+1)}=\frac{A}{rT+1}$.
Cancel common terms.
$\Rightarrow P=\frac{A}{rT+1}$.
