Answer
$P=\dfrac{A}{1+rt}$
Work Step by Step
Divide $(1+rt)$ on both sides of the equation to obtain:
$\dfrac{A}{1+rt}=\dfrac{P(1+rt)}{1+rt}$
Cancel the common factors to obtain:
$\require{cancel}
\\\dfrac{A}{1+rt} = \dfrac{P\cancel{(1+rt)}}{\cancel{1+rt}}
\\\dfrac{A}{1+rt} = P$
