《整式的加减》1、-5x-y+6x+9y= 2、(3a-2)-3(a-5)=

问题描述:

《整式的加减》1、-5x-y+6x+9y= 2、(3a-2)-3(a-5)=
3、3a²-(5a²-ab+b²)-(7ab-7b²-3a²)=

-5x-y+6x+9y
=x+8y
(3a-2)-3(a-5)
=3a-2-3a+15
=13
3a²-(5a²-ab+b²)-(7ab-7b²-3a²)
=-2a²+ab-b²-7ab+7b²+3a²
=a²-6ab+6b²