已知:ax=by=cz=1,求1⼀(1+a^4) + 1⼀(1+b^4) + 1⼀(1+c^4) + 1⼀(1+x^4) + 1⼀(1+y^4) + 1⼀(1+z^4)的值

竞赛题,帮个忙,要交的,谢谢
2025-12-16 14:52:04
推荐回答(3个)
回答1:

∵ax=by=cz=1
∴a、x;b、y; c、z三组互为倒数
∵(1/1+a*)+(1/1+x*)
=(1+a*+1+x*)/(1+a*)(1+x*)
=(2+a*+x*)/(1+a*+x*+a*x*)
=(2+a*+x*)/(2+a*+x*)=1
同理(1/1+b*)+(1/1+y*)=1
(1/1+c*)+(1/1+z*)=1
∴(1/1+a*)+(1/1+b*)+(1/1+c*)+(1/1+x*)+(1/1+y*)+(1/1+z*)
=(1/1+a*)+(1/1+x*)+(1/1+b*)+(1/1+y*)+(1/1+c*)+(1/1+z*)
=1+1+1=3

回答2:

通过合并了同类项
将有关的待a的和x的通过ax=1
带换下
1/(1+a^4)+1/(1+x^4)=1
所以最后的答案是3

回答3:

因为ax=by=cz=1
所以x=1/a,y=1/b,z=1/c所以
1/(1+a^4)+1/(1+b^4)+1/(1+c^4)+1/(1+x^4)+1/(1+y^4)+1/(1+z^4)
=[1/(1+a^4)+1/(1+x^4)]+[1/(1+b^4)+1/(1+y^4)]+[1/(1+c^4)+1/(1+z^4)]
=[1/(1+a^4)+1/(1+(1/a)^4)]+[1/(1+b^4)+1/(1+(1/b)^4)]+[1/(1+c^4)+1/(1+(1/c)^4)]
=(1/(1+a^4)+a^4/(1+a^4)+(1/(1+b^4)+b^4/(1+b^4))+(1/(1+c^4)+c^4/(1+c^4))
=(1+a^4)/(1+a^4)+(1+b^4)/(1+b^4)+(1+c^4)/(1+c^4)
=1+1+1
=3