increase per hour=increase/hours
increase=temp(final)-temp(initial)
hours=9am to 3pm
given
temp(initial)=-8
temp(final)=10
increase=10-(-8)
increase=10+8
increase=18
how many hours elapsed
9 to 12 is 3 hours
12 to 3 is 3
3+3=6
6 hours elapsed
increase per hour=18/6=3f/h
oh, you want the equation
[10-(-8)]/6 is the equation
the first one