Can somebody show I how to get to the answer F2=147 and F3=164
400+.6F2+.866F3=0
-.8F2-.5F3+400=0
rearrange things a bit to get (Using x and y for readability)
0.6x + 0.866y = -400
0.8x + 0.5y = 400
But that does not yield the answers you proposed.