To set up an equation correctly, it is important to understand the problem statement and the given values. We do as follows:
initial number of balls = 14 + 23 = 37
number of baseballs per box = 12
number of tennis balls per box = 16
we let x as the number of boxes
Total number of balls = 37 + 12x + 16x
Total number of balls = 37 + 28x