Final answer:
The football team gained 15 yards and lost 7 yards. By subtracting the yards lost from the yards gained, we find that they gained 8 yards.
Step-by-step explanation:
The football team gained 15 yards and then lost 7 yards. To determine whether the team gained or lost yards, we need to subtract the amount they lost from the amount they gained. In this case, the team gained 15 yards and lost 7 yards, so we subtract 7 from 15:
15 - 7 = 8 yards gained.
Therefore, the team gained 8 yards on the play. So the correct answer is (b) they gained 8 yards on the play.