Question

F=G m1m2/r^2 solve for G

Answer 1

The way the equation is written 

Solve for G:F = (G m^3)/r^2
F = (G m^3)/r^2 is equivalent to (G m^3)/r^2 = F:(G m^3)/r^2 = F
Divide both sides by m^3/r^2:Answer:  G = (F r^2)/m^3