# One to one function

h(x,y)=x/(y+1)

I'm not understanding why this function is NOT one to one? How do I quickly see if this function is one to one? Im not getting the overall concept of this..

HallsofIvy
$$h(2, 1)= \frac{2}{2}= 1$$
$$h(5}{4}= \frac{5}{5}= 1$$