I have been reading a lot on here about proving that a number is irrational, which has helped. But I have not seen anything when it is simply variables that are either said to be rational or irrational. Here is my question:
Prove that, if x and y are rational, x is not equal to 0, and z is irrational, y + xz is irrational, and that y +x/z is irrational.
I am not sure at all on how to approach, and unfortunately, I have been assigned this problem without it being addressed in lecture or the text. =/