Answer
$r=\dfrac{d}{t}$
$t=\dfrac{d}{r}$
Work Step by Step
To find the formula for a specific variable, simply solve for that variable by isolating it on one side of the equation.
Solve for $r$ to have:
$\\d=rt
\\\dfrac{d}{t}=r
\\r=\dfrac{d}{t}$
Solve for $t$ to have:
$\\d=rt
\\\dfrac{d}{r}=t
\\t=\dfrac{d}{r}$
