x2-y2,2xy+y2,ax+ay-bx-by的公因式是萨

题目

x2-y2,2xy+y2,ax+ay-bx-by的公因式是萨

答案

x^2-y^2=(x+y)(x-y)
2xy+y^2=y(2x+y）
ax+ay-bx-by=a(x+y)-b(x+y)=(x+y)(a-b)