Hi, could you please help with the following question. I need to understand the method in proving it's a homomorphism and then i can do other similar questions i've been asked to complete.

Let Z x Z be the ring which is the cartesian product of two copies of Z. Determine if the following is a ring homomorphism.

ZxZ -> Z, h(x,y)=x

(Z is the set of integers, and -> is an arrow)

Thanks for you help.