Just add the 'like' terms of f and g together:
(7x^2 + 2x^2) + ( -5x +4x) + (3-6) for your result.....
i´m confused i was talking about 15
f(1) means we go over on the x axis to x = 1
Then reading down to where we intersect the graph, the y value at this point = -1
f (1) = -1
Does this make sense ???