a=2-√3b=2+√3 a+b=4a-b=-2√3于是(a-b分之a+b-a+b分之a-b)÷1/a²-2ab+b²=[(a+b)/(a-b)-(a-b)/(a+b)]÷1/(a-b)²=[(a+b)/(a-b)-(a-b)/(a+b)]×(a-b)²=(a+b)/(a-b)×(a-b)²-(a-b)/(a+b)×...