Can somebody please answer these two math problems!

1. A football team gained 4 yards in one play. In the next play, the team lost 4 yards. What is
the team's net yard gain?

2. Between 8 a. m. and 3 p. m. on a summer day, the outdoor temperature increased by 23º.
Between 3 p. m. and 10 p. m., the temperature decreased by 23°. What was the net change in
temperature from 8 a. m. to 10 p. m.?