Question

把 (x+y)(x+y+1)-2 进行因式分解的结果是多少？

请把过程写详细一点，谢谢！！！！！！！！！！

Answer 1

(x+y)(x+y+1)-2
=x²+xy+x+xy+y²+y-2 ........................展开
=x²+2xy+y²+x+y-2...........................合并同类项
=（x+y）²+（x+y）+1/4-9/4..................配成完全平方和式
=（x+y+1/2）²-（3/2）².....................配成平方差式
=（x+y+1/2+3/2)（x+y+1/2-3/2）.............因式分解
==（x+y+2）（x+y+1）.......................合并同类项

Answer 2

(x+y)(x+y+1)-2=(x+y)^2+(x+y)-2=(x+y-1)*(x+y+2)