Ok well, I have used up 2 out of 3 of my submissions for this question. I have tried to do a system of equations and failed twice. I really don't even know where to start so I was hoping that you guys could help me. The problem is. The mass of a robot is 5720 kg. This robot weighs 3720 N more on planet A than it does on planet B. Both planets have the same radius of 1.33x10^7 m. What is the difference MA - MB in the masses of these planets? Thank you.