Touba M. answered 02/20/20
B.S. in Pure Math with 20+ Years Teaching/Tutoring Experience
For finding the volume, first of all you need to find the area of square.
so you need the side of square , in this case side square is Y = 4 - X
Graph y+x = 4 and choose one point on the line the order pair of this point is (X,4-X)
area = (4 -X)^2
V = ∫area dx bounded x=0 t0 x = 4 ( x = 4 is x-int y +x =4)
V = ∫(4-X)^2 dx
V = -1/3 (4-x)^3
V = -1/3(0) + 1/3(4-0)^3
V = 64/3
I hope it is useful,
Minoo