If g is (10,11) and h is (11, -5), what is g+h?

We're just adding the x coordinates and the y coordinates to get the result...so we have

(10 + 11, 11 + (- 5))  =  (21, 6) = g + h

Think of it this way...If we are plotting the point (2,3), aren't we really just adding 2 and 3 to the coordinates of the origin, (0, 0) ???

Hope that helps......