Answer
f=7.2
Work Step by Step
We need to get f only on one side, so we subtract by f on both sides to get that $6-1.25f=-3$. We need to get the f alone. Thus, we cancel out the addition by subtracting 6 on both sides. This leaves us with the equation $-1.25f=-9$. In order to cancel out multiplication, we use division, so we divide both sides of the equation by -1.25 to get that f=7.2.