[2x²+ax-y+6]-[2bx²-3x+5y-1]
=2x²+ax-y+6-2bx²+3x-5y+1
=(2-2b)x²+(a+3)x-6y+7
2-2b=0
b=1
a+3=0
a=-3
1/3a³-2b²-[1/4a³-3b²]
=(1/3+1/4)×(-3)³+(3-2)×1²
=7/12×（-27）+1
=-189/12+1
=-15又3/4+1
=-14又3/4
[2x²+ax-y+6]-[2bx²-3x+5y-1]
=2x²+ax-y+6-2bx²+3x-5y+1
=(2-2b)x²+(a+3)x-6y+7
2-2b=0
b=1
a+3=0
a=-3
1/3a³-2b²-[1/4a³-3b²]
=(1/3+1/4)×(-3)³+(3-2)×1²
=7/12×（-27）+1
=-189/12+1
=-15又3/4+1
=-14又3/4