(2x²+ax-y+6)-(2bx²-3x+5y-1)
=2x²+ax-y+6-2bx²+3x-5y+1
=(2-2b)x²+(a+3)x-6y+7
由题意得知跟X无关
所以2-2b=0 b=1
a+3=0 a=-3
1/3a³-3b²-(1/4a³-2b²)
=1/3a³-3b²-1/4a³+2b²
=1/12a³-b²
=-27/12-1
=-39/12
(2x²+ax-y+6)-(2bx²-3x+5y-1)
=2x²+ax-y+6-2bx²+3x-5y+1
=(2-2b)x²+(a+3)x-6y+7
由题意得知跟X无关
所以2-2b=0 b=1
a+3=0 a=-3
1/3a³-3b²-(1/4a³-2b²)
=1/3a³-3b²-1/4a³+2b²
=1/12a³-b²
=-27/12-1
=-39/12