Step-by-step explanation:
integral fx = gx, gx = fx
gx = -4x2
variable of x2 = replace to left side it mean we got minus when Variable replace to left it mean minus
Honestly, I have no idea what it means by decomposition, but this is my best bet on what it means: Dividing the polygon into smaller, easier sections and solve for area and add them up.
Correct Answer to this question is 4