Three different forces act on an object. They are:
F1 = < - 3, 5 >
F2 = < 4, - 8 >
F3 = < 5, 2 >
Find the net force Fnet on the object (the sum of the forces)
Fnet =
Find what fourth force, F4 would need to be added so the object feels no force, that is, so Fnet = 0
F4 =