-22 = 11d
Now divide by 11 both sides
-2 = d
You can work on either side of the equation, I used the right side for the variables because it was easier to add to positive numbers than dealing with negative numbers on the left side:
-7d -4d = 22
d = -2
either way you get the same answer :)
40% off the regular price is the correct answer.
just put √(2) * √(32) into a calculator. that will make the answer be 8.