We start with f(x)=4x+9.
Placing a " - " sign in front of the x term will reflect the graph of y=4x about the x-axis, but will not change the effect of that constant +9.
After this reflection your graph will still go through (0,9), but will have a slope of -4 instead of one of +4.
So, we'll end up with a line of slope m = -4 whose y-intercept is still (0,9). Translating this graph downward by 2 units will result in the graph of
y = -4x + 7.
