Answer:
1
-------------
(x+2)(x-4)
Explanation:
x+4 x+3
------------- * --------------
x^2+5x+6 x^2 -16
Factor
x+4 x+3
------------- * --------------
(x+3)(x+2) (x+4)(x-4)
Cancel like terms
1 1
------------- * --------------
(1)(x+2) (1)(x-4)
1
------------- x cannot equal -3, -4, -2, 4
(x+2)(x-4)