Does work? Why or why not?
Its a function f(g(x))=h correct? So you take the function of g, which in this case we found to be x^2+x-1 and plug that into the x values of f(x).
Doing so will give you 2(x^2+x-1)+8.
Factoring out will give you 2x^2+2x-2+8, add like terms and you will come to h, which is 2x^2+2x+6!