Find Undefined

1.  For which of the following values of x is $\dfrac{3+x}{x-3}$ undefined?

1. -3
2. 0
3. 3
4. There is no such value.

2.  For which of the following values of a is $\dfrac{a-2}{-a+2}$ undefined?

1. -2
2. 0
3. 2
4. There is no such value.

3.  For which of the following values of x is $\dfrac{2(y+2)}{-3(y-2)}$ undefined?

1. 2
2. 3
3. 4
4. There is no such value.

$g(x)=\dfrac{1}{(x-4)^2+5(x-4)+6}$

4.  What is a value of x that will make the function $g$ above undefined?