Hello gents. Trying to help my girlfriend's daughter with some math & I didn't realize how bad I am with algebra. I'm not looking for an answer. Just an explanation on how this is solved. Any help is appreciated.

The question is:

Solve for the indicated variable

4/xy + 16/xz + 20/yz = 12

Solve for y.
I'm thinking divide by Y. I've been out of high school too long.