The solution occurs where the two lines intersect. From this intersection point, draw a vertical line upward until you reach the x axis. We arrive somewhere between -5 and -6. A good estimate is to say that we're at the midpoint, so x = -5 & 1/2 is one possible estimate
Since only choice D has this x value, this must mean choice D is the answer. The y coordinate of y = -3 & 1/4 seems to fit as well since we can draw a horizontal line from the point of intersection to the y axis, and arrive somewhere just a little below -3.
Nope. Her solution doesn't seem reasonable. In order to subtract 9/12 from 10 7/12 you must convert 10 7/12 to an improper fraction. You should then have 127/12 where she has 10/12.
