How you start the equation is by plugging 3 into both of the x 's in the problem to make it: f ( 3 ) = 3 ( 3 ) − 4 Next, you multiply the 3 ( 3 ) to get 9 and subtract 4 . So in the end, you leave the f ( 3 ) and 9 − 4 is 5 , so the y in the equation is 5 . The answer would be written as f ( 3 ) = 5
