Determine the mass of the planet and whether an astronaut

Question

You are on a deep space mission to search for Earth-like planets. Your crew locates a possible planet and with scanners finds the radius to be 7.5 x 10⁶ m. A team lands on the surface. There, they hang a 1.0 kg mass from a spring scale. It reads 8.5 N. Determine the mass of the planet and whether an astronaut standing on this new planet weighs more, less, or the same

Equation needed:

F = (GMm )/ r²

Given:

F=8.5

G=6.67e-11

m=1

r=7.5e6

unknown:

M=?

I think this is what the question represents and what i am give. What steps would i follow to re-arrange the question in order to solve for M