Question

把下列各多项式因式分解1.a²-b²-2b-12.（a-b）²+4ab3.（x+y）&su

Answer 1

1.原式=a2-(b2+b+1)=(a+b+1)(a-b-1)

2.(a+b)2

3.原式=(x+y)2-4(x+y)+4=(x+y-2)2