12 pounds of apples cost 6 dollars how much is 3 pounds

The graph of f(x), shown below, resembles the graph of g(x) = x2, but it has been changed somewhat. which of the following could be the equation of f(x)?

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)

Me. i can't figure out this question. give an explanation too. .