#### Answer

$t=\dfrac{A-P}{Pr}$

#### Work Step by Step

Using the properties of equality, in terms of $
t
,$ the given formula, $
A=P(1+rt)
,$ is equivalent to
\begin{array}{l}\require{cancel}
A=P+Prt
\\\\
A-P=Prt
\\\\
\dfrac{A-P}{Pr}=t
\\\\
t=\dfrac{A-P}{Pr}
.\end{array}