range is {- 27, - 15, - 3, 9 }
substitute each of the values from the domain into the equation for x and solve for y
These values are the range
x = - 2 : y = - 12 - 15 = - 27
x = 0 : y = 0 - 15 = - 15
x = 2 : y = 12 - 15 = - 3
x = 4 : y = 24 - 15 = 9
