2.我們規(guī)定:使得a-b=ab成立的一對數(shù)a,b為“積差等數(shù)對”,記為(a,b).例如:因?yàn)?.5-0.6=1.5×0.6,(-2)-2=(-2)×2,所以數(shù)對(1.5,0.6),(-2,2)都是“積差等數(shù)對”.
(1)判斷下列數(shù)對是否是“積差等數(shù)對”:
①(1,
)
(填“是”或者“否”);
②(2,1)
(填“是”或者“否”);
③(
,-1)
(填“是”或者“否”);
(2)若數(shù)對(m,3)是“積差等數(shù)對”,求m的值;
(3)若數(shù)對(a,b)是“積差等數(shù)對”,求代數(shù)式4[3ab-a-2(ab-2)]-2(3a
2-2b)+6a
2的值.