A math problem. Simplify first, then calculate [(2x+y)²-y(y+4x)-8x]/2x x=10

A math problem. Simplify first, then calculate [(2x+y)²-y(y+4x)-8x]/2x x=10

[(2x+y)²-y(y+4x)-8x]/2x
=[4x^2+4xy+y^2-y(y+4x)-8x]/2x
=(4x^2-8x)/2x
=2x-4
Because x = 10
So the original formula is: 16