（x²+x)²-26(x²+x)+120 ax+ay+bx+by-a-b x²(x²-y²)-72y⁴

너 이거 화 간 이지?x)²-26(x²+x)+120 =(x²+x-6)(x²+x-20)=(x-2)(x+3)(x-4)(x+5)
ax+ay+bx+by-a-b=a(x+y)+b(x+y)-(a+b)=(x+y)(a+b)-(a+b)=(a+b)(x+y-1)
x²(x²-y²)-72y⁴=x⁴-x²y²-72y⁴=(x²+8y²)(x²-9y²)=(x²+8y²)(x-3y)(x+3y)