At 9: 00 a.m. it was -8º f. at 3: 00 p.m. the temperature was 10º f.

which expression shows how to find the average increase per hour in temperature?

[10−(-8)]÷6

[10+(-8)]÷6

6÷(−8+10)

6÷[−8−(−10)]

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

D becuse it's over 1 and it's the most sinplified