-x的二次方+(2x的二次方-3x)-5(x-2)
=-x²+2x²-3x-5x+10
=x²-8x+10
=(-3/2)²+8x3/2+10
=9/4+12+10
=26又1/4
(a的二次方-ab-二分之一b的二次方)-4(a的二次方+ab-0.25b的二次方)
=a²-ab-1/2b²-4a²-4ab+b²
=-3a²-5ab+1/2b²
=-3x(-3)²+5x3x4+1/2x4²
=-27+60+8
=41
-x的二次方+(2x的二次方-3x)-5(x-2)
=-x²+2x²-3x-5x+10
=x²-8x+10
=(-3/2)²+8x3/2+10
=9/4+12+10
=26又1/4
(a的二次方-ab-二分之一b的二次方)-4(a的二次方+ab-0.25b的二次方)
=a²-ab-1/2b²-4a²-4ab+b²
=-3a²-5ab+1/2b²
=-3x(-3)²+5x3x4+1/2x4²
=-27+60+8
=41