Solve for x (C++)

Question

What is the value of x after the following statements?

int x;

x = 0;
x = x * 30;

1. 0
2. 30
3. 33
4. not defined

I have the answer as 4, undefined, but why is that?

Is it because if you solve for x mathematically, it is 0x = 30, which can't be?

Answer 1

only if you are dividing by 0 would complier complains.