急数学题化简已知 -b²+14ab+A=7a²+4ab-2b²,则A= ______化简 2（a+1）-a= ______多项式______与m²+m-2是和m²-2m.

急数学题化简已知 -b²+14ab+A=7a²+4ab-2b²,则A= ______化简 2（a+1）-a= ______多项式______与m²+m-2是和m²-2m.
急数学题化简
已知 -b²+14ab+A=7a²+4ab-2b²,则A= ______
化简 2（a+1）-a= ______
多项式______与m²+m-2是和m²-2m.

急数学题化简已知 -b²+14ab+A=7a²+4ab-2b²,则A= ______化简 2（a+1）-a= ______多项式______与m²+m-2是和m²-2m.

A=7a²-10ab-b²

a+2

2-3m