# Thread: 3^x = 4^y = 12^z

1. Greetings, I have an equations that needed to be proved.
3^x = 4^y = 12^z

show that z = (xy)/(x+y) from the above equation  2. ### Related Discussions:

• Originally Posted by TzerMaan
Greetings, I have an equations that needed to be proved.
3^x = 4^y = 12^z

show that z = (xy)/(x+y) from the above equation
This is pretty clearly homework. We won't do your work for you.

You have also neglected the solution x=y=z=0.  • i hope its not homework, so having that said, i will help you.

you have to make use of logarithms.

so you have two equations,  so taking log, (i assume you have knowledge in logarithms)

xlog3=ylog4-----------1
ylog4=zlog12-----------2

now if we see equation 2, it becomes;  now we know that log3=ylog4/x
so if we substitute this in to equation2,     Bookmarks
 Posting Permissions
 You may not post new threads You may not post replies You may not post attachments You may not edit your posts   BB code is On Smilies are On [IMG] code is On [VIDEO] code is On HTML code is Off Trackbacks are Off Pingbacks are Off Refbacks are On Terms of Use Agreement