4friends evenly divided up a n- slice pizza. one of the friends , harris, ate 1 fewer slice than he received. how many slices of pizza did harris eat?

4 friends evenly dividing up a n - slice pizza

So each one get slices of pizza.

 For example, if n = 12 slice then each friend gets 12/4 = 3 pieces.  If Harris ate one slice less then he ate  =3 -1 =  2 pieces.

So the general expression for slices of pizza did Harris eat is