two planets of mass "m" and "M" respectively. Have centre to centre seperation of "R" . At what distance from the centre of the planet of mass "M" do the gravitational force of planets cancel each other??????? plz urgent help me?

Answer 1

G•m(o)•M/x^2 = G•m(o)•m/(R-x)^2,
m/M = (R-x)^2/x^2,
Since all numbers are positive,
sqrt(m/M) = (R/x) -1.
x = R/[1 +sqrt(m/M)]