1.3ab-4ab+8ab-7ab+ab a=1,b=2
2.2y+(-2y+5)-(3y+2) x=3,y=4.5
3.已知A=x3-2x2+x-4，B=2x3-5x+3，计算A+B
4.5(x-2y)2-3(-x+2y)-100 , 2y-x=5
5.9a2+[7a2-2a-(-a2+3a)]= a=6
望采纳
1.3ab-4ab+8ab-7ab+ab a=1,b=2
2.2y+(-2y+5)-(3y+2) x=3,y=4.5
3.已知A=x3-2x2+x-4，B=2x3-5x+3，计算A+B
4.5(x-2y)2-3(-x+2y)-100 , 2y-x=5
5.9a2+[7a2-2a-(-a2+3a)]= a=6
望采纳