Answer:
x = - 4
Explanation:
Given
y =

The denominator of y cannot be zero as this would make y undefined.
Equating the denominator to zero and solving gives the value that x cannot be and if the numerator is non zero for this value then it is a vertical asymptote.
x + 4 = 0 ⇒ x = - 4
Thus the vertical asymptote is x = - 4