(6a²-2ab)-2(3a²+4ab-1/2b²),其中,A=1/5,b=-1

问题描述:

(6a²-2ab)-2(3a²+4ab-1/2b²),其中,A=1/5,b=-1

(6a²-2ab)-2(3a²+4ab-1/2b²)
=6a²-2ab-6a²-8ab+b²
=-10ab+b²
=-10×1/5×(-1)+(-1)²
=2+1
=3