Translating the worded problem into mathematical form, the following expression was obtained: ( 8x - 56 / x^2 - 49 ) / (x - 6 / x^2 + 11x + 28)
Simplifying:
( 8x - 56 / x^2 - 49 ) ( x^2 + 11x + 28 / x - 6)
Factoring out:
( 8(x-7) / (x+7)(x-7) ) ( (x+7)(x+4) / x - 6 )
Cancelling out (x-7) and (x+7):
8(x+4) / (x-6)
Therefore, the correct answer is D.