Answer
$r = \sqrt {\frac{GmM}{F}}$
Work Step by Step
$Solve$ $the$ $equation$ $for$ $the$ $indicated$ $variable:$
$F = G\frac{mM}{r^2};$ $for$ $r$
Solve for $r$
Multiply both sides by $r^2$
$r^2\times F = r^2(G\frac{mM}{r^2})$
$r^2F = GmM$
Divide both sides by $F$
$\frac{r^2F}{F} = \frac{GmM}{F}$
$r^2 = \frac{GmM}{F}$
Square root both sides
$\sqrt {r^2} = \sqrt {\frac{GmM}{F}}$
$r = \sqrt {\frac{GmM}{F}}$
