Sure. Let's take an example with numbers instead of variables. 8/9 is a rational number - the ratio of two integers. If you square it, you get (8/9)2 = 82/92 = 64/81; that is, if you square each...
Unless you multiply 0 with some irrational number, it is impossible. Here's why: Let x,y be rational with x = a/b, z = c/d and y be the irrational number. If we presume xy = z then we have y = z/x....