(6a^2-2ab)-2(3a^2+4ab-1/8b^2)其中A+1/5,b=-1五分钟内回答!

(6a^2-2ab)-2(3a^2+4ab-1/8b^2)
=6a²-2ab-6a²-8ab+1/4b²
=-10ab+1/4b²
=-10*1/5*(-1)+1/4
=2+1/4
=9/4

(6a^2-2ab)-2(3a^2+4ab-1/8b^2)
=6a^2-2ab-6a^2-8ab+1/4b^2
=-10ab+1/4b^2
=-10*1/5*(-1)+1/4*(-1)^2
=2+1/4
=2又1/4