a/3=b/4=c/5,求a²+b²+c²/ab+bc+ca
设a/3=b/4=c/5=t,则:
a=3t,b=4t,c=5t
(a²+b²+c²)/(ab+bc+ca)
=(9t²+16t²+25t²)/(12t²+20t²+15t²)
=50/47
a/3=b/4=c/5,求a²+b²+c²/ab+bc+ca
设a/3=b/4=c/5=t,则:
a=3t,b=4t,c=5t
(a²+b²+c²)/(ab+bc+ca)
=(9t²+16t²+25t²)/(12t²+20t²+15t²)
=50/47