【趣味算法】当a=b时，1=2。

              假如 a=b 时，

 

                   a=b

                   ===> a² = ab

                   ===> a² - b²  = ab-b²

                   ===> (a+b)(a-b) = b(a-b)

                   ===> a+b = b

                   ===> a+a = a

                   ===> 2a=a

                   ===> 2=1