f(1) is equal to 1^2-8, or -7.
g(x) is (-7+1)/-7, or -6/-7. This simplifies to 6/7. C is the best option.
Also, since you posted a similar question earlier, I knew what to look for with g(x), but in the future, this looks like the x is not divided by the x in the denominator, and you should express this function as (x+1)/x to increase clarity.