PHYSICS CIRCULAR MOTION GRAVITATIONAL CONSTANT
posted by Jaylee .
Three masses are arranged in an (x, y)
plane.
7 kg (3,1)
8 kg (0,0)
9 kg (1,2)
a) What is the magnitude of the resulting force on the 8 kg mass at the origin? The universal gravitational constant is 6.6726 × 10^−11 N · m^2/kg^2. Answer in units of N.
b) What is the angle of the resultant force on the 9 kg mass at the origin?

For b): I meant the resultant force on the 8 kg mass at the origin. Sorry!

calculate the two forces, magnitude and angle, add them. Compare it to this:
fx=G7*8/9 (x) + G9*8/1 x add them to get net force in x direction.
fy=G7*8/1(+y) + G9*8/4 (+y) add them to get net force in y direction
Now add these as vectors. 
I'm sorry, but I'm not understanding your explanation. I figured out the two forces and found the resultant but my answer is wrong and I'm not sure how to use your method.

What does the G stand for? The gravitational constant??