(2x^2+ax-y+6)-2bx^2-3x-5y-1
=(2-2b)x^2+(a-3)x-6y+5 与x无关
则x的系数为0
2-2b=0,b=1
a-3=0,a=3
1/3×a^3-2b^2-(1/4×a^3-3b^2)
=1/3×3^3-2-(1/4×3^3-3)
=9-2-15/4=13/4
(2x^2+ax-y+6)-2bx^2-3x-5y-1
=(2-2b)x^2+(a-3)x-6y+5 与x无关
则x的系数为0
2-2b=0,b=1
a-3=0,a=3
1/3×a^3-2b^2-(1/4×a^3-3b^2)
=1/3×3^3-2-(1/4×3^3-3)
=9-2-15/4=13/4