解
4(2x-y)²-(2x+y)²
=[2(2x-y)]²-(2x+y)²
=[2(2x-y)-(2x+y)][(2(2x-y)+(2x+y)]
=(4x-2y-2x-y)(4x-2y+2x+y)
=(2x-3y)(6x-y)