B-2A=2y²+5ay-2y-1-2(y²+ay-1)=(3a-2)y+1∵字母y的取值无关∴3a-2=0∴a=2/3
B-2A=2y²+5ay-2y-1-2(y²+ay-1)=2y²+5ay-2y-1-2y²-2ay+2=3ay-2y+1=(3a-2)y+1与字母y的取值无关 3a-2=0a=2/3
