12. the change in temperature is -1 C. -3 C + -1 C= -4 C
13. The net gain. Lin gained 14 yards, then loss 7 yards, and lastly gained 9 yards
14 + (-7) + 9= 16 yards
14. Pythagoras was born 582 BC. Newton 1643 AD
1643-582= 1,061 years
15. Sonny has $75 but he needs to buy something costs $93
he needs to borrow $18.
93-75= $18