we are given

(a)
We know that when denominator of any function is 0
then function will become undefined
so, denominator=0 will make function no solution
so, we set denominator =0
and then we solve for x

............Answer
(b)
Vertical shift:
Suppose, we want to shift y=f(x) function vertically by 'c' units
we add 'c' top y-value
so, new function will become

now, we have
If g(x) is a vertical shift of 4 units of f(x)
so, we can write our function as

we can plug f(x)

Comparison:
So, graph of f(x) is moved upside by 4 units to get graph of g(x)
(c)
We can set g(x)=8
and then we can solve for x

Multiply both sides by x+4





..............Answer