(2x的平方+ax-y+6)-(2bx的平方-3x+5y-1)
=(2-2b)x²+(a+3)x-5y+7
2-2b=0
b=1
a+3=0
a=-3
1/2a²-2b²+4ab
=1/2x(-3)²-2x1²-4x3x1
=9/4-2-12
=-11又3/4
(2x的平方+ax-y+6)-(2bx的平方-3x+5y-1)
=(2-2b)x²+(a+3)x-5y+7
2-2b=0
b=1
a+3=0
a=-3
1/2a²-2b²+4ab
=1/2x(-3)²-2x1²-4x3x1
=9/4-2-12
=-11又3/4