Proving that a parametric equation define a specific surface

Question

Exercise 2b, §2, chapter 3 of "Using algebraic geometry" by D. Cox, J. Little and D. O' Shea asks the reader to show that the parametric equations $(x,y,z)=(st,s^2t,st^2)$ define the surface $x^3=yz$. Now, this is most probably a very easy question since the difficult part comes after, but I have some trouble. Any help would be appreciated!

Answer 1

$$x=st,y=s^2t,z=st^2$$ $$yz=s^3t^3=(st)^3=x^3$$