Question

已知代数式2x^2+ax-y+6-2bx^2+3x-5y-1的值与字母x的取值无关,求1/3a^3-2b^2-1/4a^

Answer 1

代数式2x^2+ax-y+6-2bx^2+3x-5y-1的值与字母x的取值无关,

2-2b=0,b=1

a+3=0,a=-3

1/3a^3-2b^2-1/4a^3+3b^2

=-9-2+27/4+3

=-11+6+3+3/4

=-5/4