In a series of plays a football team gains 20 yards, gains 15 yards, and then lose 7 yards. What is the total gain or loss in yardage?

This is wrong

20 + 15 - 7 = ?

To find the total gain or loss in yardage, we need to add up the gains and subtract the loss.

First, let's add the gains:
20 yards + 15 yards = 35 yards

Next, let's subtract the loss:
35 yards - 7 yards = 28 yards

Therefore, the total gain or loss in yardage is 28 yards.