①（x²+y²-1）²-4x²y²②a(2a-b)+2a(b-2a)²-a(b-2a)²-a（(b-2a)三次

Question

①（x²+y²-1）²-4x²y² ②a(2a-b)+2a(b-2a)²-a(b-2a)²-a （(b-2a)三次

Answer 1

原式=(x²+2xy+y²-1)(x²-2xy+y²-1)
=[(x+y)²-1][(x-y)²-1]
=(x+y+1)(x+y-1)(x-y+1)(x-y-1)
原式=a(2a-b)+2a(2a-b)²-a(2a-b)²+a(2a-b)³
=a(2a-b)+a(2a-b)²+a(2a-b)³
=a(2a-b)[1+(2a-b)+(2a-b)²]
=a(2a-b)(4a²-4ab+b²+2a-b+1)