你答的当X=1984,Y=1916时,计算:(X的四次方-Y的四次方/X的二次方-2XY=Y的二次方)×(Y-X/X中用计算器算为390怎么回事啊
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/02 02:41:26
![你答的当X=1984,Y=1916时,计算:(X的四次方-Y的四次方/X的二次方-2XY=Y的二次方)×(Y-X/X中用计算器算为390怎么回事啊](/uploads/image/z/601356-12-6.jpg?t=%E4%BD%A0%E7%AD%94%E7%9A%84%E5%BD%93X%3D1984%2CY%3D1916%E6%97%B6%2C%E8%AE%A1%E7%AE%97%3A%28X%E7%9A%84%E5%9B%9B%E6%AC%A1%E6%96%B9-Y%E7%9A%84%E5%9B%9B%E6%AC%A1%E6%96%B9%2FX%E7%9A%84%E4%BA%8C%E6%AC%A1%E6%96%B9-2XY%3DY%E7%9A%84%E4%BA%8C%E6%AC%A1%E6%96%B9%29%C3%97%28Y-X%2FX%E4%B8%AD%E7%94%A8%E8%AE%A1%E7%AE%97%E5%99%A8%E7%AE%97%E4%B8%BA390%E6%80%8E%E4%B9%88%E5%9B%9E%E4%BA%8B%E5%95%8A)
你答的当X=1984,Y=1916时,计算:(X的四次方-Y的四次方/X的二次方-2XY=Y的二次方)×(Y-X/X中用计算器算为390怎么回事啊
你答的当X=1984,Y=1916时,计算:(X的四次方-Y的四次方/X的二次方-2XY=Y的二次方)×(Y-X/X中用计算器算为390
怎么回事啊
你答的当X=1984,Y=1916时,计算:(X的四次方-Y的四次方/X的二次方-2XY=Y的二次方)×(Y-X/X中用计算器算为390怎么回事啊
(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、
(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