Question

将(x+y)、(a-b)分别作为一个整体，合并同类项

(1) 2(a-b)-八分之五(a-b²)-三分之2(a-b)+3(b-a)²+2
(2) 3(x+y)²-9(x+y)-8(x+y)²+6(x+y)-1

Answer 1

3(x+y)²-9(x+y)-8(x+y)²+6(x+y)-1=【3(x+y)²-8(x+y)²】+【6(x+y)-9(x+y)】-1=-5（x+y）²-3（x+y）-1

追答