ANSWER
a=1
b=-12
EXPLANATION
The function has a hole at
x=3
The function also have a vertical asymptote at
x=-4.
This implies that, the denominator of the function is
[tex](x - 3)(x + 4) [/tex]
[tex] {x}^{2} + 4x - 3x - 12[/tex]
[tex]{x}^{2} + x - 12[/tex]
Comparing this to the function in the denominator,
[tex] {x}^{2} + ax + b[/tex]
we have
a=1 and b=-12
