the function would do 3 things
1. flip horizontally, because of the negative applied to the slope
2. widen, because of a fractional slope between -1 and 0 (-2/7 makes the rise shorter than the run, so the function widens by going 7 units out for every 2 units down)
3. shift down 7 units, because the initial y-intercept would be changed from, say, 8 to 1. this would bring the graph downwards by 7 units
