got his as a homework question and not sure if it is a misprint or this is the proper equation. Either way, got no clue how to proceed.
2^x = 5^y = 10^z
using logarithms to base 10 or otherwise, show that 1/z = 1/x + 1/y
i am thinking one of those equal signs is really a plus maybe a minus???
any help greatly appreciated.