For all the other viewers of this question, the change was -403 feet or you could say 403 feet i guess but the answer is -403 feet
X-y=3=>x=3+y
X+2y=-6
=========
3+y+2y=-6
3+3y=-6
3y=-6-3
3y=-9
y=-3
X+2y=-6
X+2(-3)=-6
X-6=-6
X=0
A = 1/2 b h
5 = 1/2 (5) h
10 = 5h
h = 10/5
h = 2
answer
2