What is the range of change of the function f(x) =3x-12 for the domain (-2,2)?

The range is simply the output.

This is asking for to find the range of values for between x = -2 and for x =2

f(x) = 3x - 12

for x = -2,  f(-2) = 3*(-2) - 12 = -6 - 12 = -18

for x = 2,  f(2) = 3*(2) - 12 = 6 - 12 = -6

Therefore range of values for f(x) is between -18 and -6

 Range is:    (-18, -6) 

25 divided by 4 is 6.25
So 1 gallon is 6.25 pounds