sixteen is divided by the sum of a number q and 1. the result is four. what is the number

16 / [q + 1] = 4      multiply both sides by q + 1

16 = 4[q + 1]          simplify

16 = 4q + 4            subtract 4 from both sides

12 = 4q                   divide by 4 on both sides

3 = q