All the r in your first equation are the same. r is the distance from the center of Krypton to the center of its moon. The r in the second equation is the radius of the planet. I assume that Fg is the force of gravity, or weight at the planet's surface. If that is what you mean, then you should have the correct result.

Yes thats what i meant. The other r (the one in the 2nd equation) is the radius. So i know how to set it up, the problem is im not good at plugging it in. What am i doing wrong?

m1/3.6x10^17=39.47 r/t^2
m1/3.6x10^17=39.47 (6x10^8)/1.194x10^13
when i solve for m1 i get 6.84x10^14...that doesnt seem right?

and if its right, how do u multiply that times 70 kg...which is m2?

It doesn't look right, but you have not included enough steps to find out what you are doing. I suggest you solve the equation algebraically for m1 before entering any numbers,

m1/r^2=4pi^2 r/t^2
thats basically as far as i can solve it...
plug in 345600 for t, and 6x10^8 for r, then its just basic calculator plug ins from there getting m1/r^2=.0019...so what am i doing wrong?

Then...
Gm1=39.478 r^3/3456000^2
Gm1=39.478 r^3/1.194x10^13
then you devide each side by G...so what am i doing wrong? Maybe im taking r^3 wrong? How do you do that just to make sure im doing it right.

Gm1=4pi²*r³/t²
m1=4*pi²*r³/(t²*G) = 1.07 x 10^25 kg on my calculator

Edit: The original value posted was incorrect because it used the OP's value for t that was off by a factor of 10. The value in the quote has been corrected, and the correction for m1 made here

can u show me the steps because i still cant get that answer...i get like 7.139x10^13, then i multiply it by 70 and 9.8 and divide it by (6.4x10^6)^2 and get 1195. Howd u get 1.07x10^27? What do you do after you get it? if u plug it in to the 2nd equation you get a crazy number.