Help! Zero gravitational force

[cgotu2]

The problem says to find the point between Mars and the Sun at which an object can be placed so that the net gravitational force exerted by Mars and the Sun on that object is zero.

Here is what I've done so far, but i'm not getting the correct answer:

F(sun) = F(mars)

Gm0*msun/r^2=Gm0*mmars/(D-r)^2

then cancelling out common factors the equation becomes: msun/r^2=mmars/(D-r)^2

D is the separation between mars and the sun and i have the mass of the sun and mars...so why am i not getting the right answer? Please help!!!

[whozum]

Just plug in your numbers now..what you've got is fine.

[andrevdh]

I think you need to show us how you actually got to the answer so that we can see were you went wrong. It is actually just solving for the roots of an quadratic equation problem.