①由题意得:(-2x2+3)-2A=2x2+2x-7
则2A=-2x2+3-2x2-2x+7=-4x2-2x+10;
所以A=-2x2-x+5;
由于2x=-1得x=-[1/2],
将x的值代入A得A=-2×[1/4]+
1
2+5=5.
②由分析得:(1)2※3=3×3-6×2+2=-1;
(2)([1/2]※[2/3])※(-2)=(3×[2/3]−6×
1
2+2)※(-2)=1※(-2)=3×(-2)-6×1+2=-10.
(3)a※(2a+3)=3(2a+3)-6a+2=6a+9-6a+2=11.