f(x) = 3 / { x + 3] - 9
The vertical asymptote is the value of x that makes the denominator = 0
So....
x + 3 = 0
x = - 3 ⇒ vertical asymptote
To find the horizontal asymptote.....note that 3/ [ x +3 ] is a lower power polynomial / higher power polynomial
When we have this situation, the horizontal asymptote is y = 0
However ..... the "-9" at the end actually shifts this horizontal aymptote DOWN by 9 units
So....the horizontal asymptote is y = - 9
Here's the graph : https://www.desmos.com/calculator/93af4udovt