Question

19961997*19971996-19961996*19971977谁知道最简单的方法算出来?

19961997*19971996-19961996*19971997上面的错了..

Answer 1

上式可以写成xy-(x-1)(y+1)=xy-(xy+x-y-1)=y-x+1
题中:x=19961997 y=19971996
代入,得答案=10000

Answer 2

19961997*19971996-19961996*19971977
=(19961996+1)*(19971997-1)-19961996*19971997
=19961996*19971997-19961996+19971997-19961996*19971997
=19971997-19961996-1
=10001-1
=10000

Answer 3

设a=19961996
原式=(a+1)(a+10000)-a*(a+10001)
=a*a+10001a+10000 - a*a - 10001a
= 10000

Answer 4

设a=19961996
原式=(a+1)(a+10000)-a*(a+10001)
=a*a+10001a+10000 - a*a - 10001a
= 10000