(X^4-Y^4)/(X²-2XY+Y²) × (Y-X)/(X²+Y²)
=(X²+Y²)(X²-Y²)/(X-Y)² × (Y-X)/(X²+Y²)
=(X²+Y²)(X-Y)(X+Y)/(X-Y)² × [-(X-Y)/(X²+Y²)]
=(X+Y)/(X-Y) × [-(X-Y)]
=-X-Y
=-1984-1916
=-3900
如果用计算器,那么带入
=(15494111297536-13476652155136)/4624 × (-68)/(3936256+3671056)
=2017459142400/4624 × (-68)/7607312
最后算出来也是-3899.9923100……
计算器有点出入的,小数不会约分,可能你哪里按错了.
有什么不懂的可以追问、帅哥（美女），你好聪明啊，我的确按错了。我不帅……