把（a+b）,（a-b）,（x+y）,（x-y）作为一个因式,合并同类项1.3(x+y)²2-7(x-y)-9(x+y)²2-6(x-y)2.3(a-b)+6(a+b)-2(a+b)+6(a-b)
问题描述：
把（a+b）,（a-b）,（x+y）,（x-y）作为一个因式,合并同类项
1.
3(x+y)²2-7(x-y)-9(x+y)²2-6(x-y)
2.
3(a-b)+6(a+b)-2(a+b)+6(a-b)
答
1 3(x+y)²2-7(x-y)-9(x+y)²2-6(x-y)=-6(x+y)^2-13(x-y)
2 3(a-b)+6(a+b)-2(a+b)+6(a-b)=9(a-b)+4(a+b)
答
1.
3(x+y)²-7(x-y)-9(x+y)²-6(x-y)
=-6(x+y)²-13(x-y)
2.
3(a-b)+6(a+b)-2(a+b)+6(a-b)
=9(a-b)+4(a+b)