a=1,-3小于b小于负根号三且b为整数,b=-2(a-2ab-b²)/a乘以(a²+ab)/(a²-b²)=（a-2ab-b²/a乘以a(a+b)/[(a+b)(a-b)]=（a-2ab-b²)/(a-b)=（1-2b-b²)/(1-b)=(1+4-4)/(1+2)=1/3...