This is from the P1 review in my calculus book. I have a few problems that stumped me.

1. Find any intercepts for:
x^2y-x^2+4y=0
The answer is (0,0), but I do not know how to do the problem.

2. Find any intercepts for:
3(2-sqrt.X) / x
Again, I know the answer (4,0), but need to know how to do it.

3. Find points of intersection for:
y=x^3
y=x
The answer is (-1,-1);(0,0);(1,1).

Thanks for any/all solutions!