For the function f(x) = 5- 4x, what is the rate of change? For the above function, what is the y-intercept?

Let's write this in y = mx + b form where m is the rate of change (i.e., the slope) and b is the y intercept....so we have

y = -4x + 5

So...the slope is -4 (y changes by -4 when x changes by +1) and the y intercept is at 5 .....or, the point (0, 5)

This graph is a stretch parallel to the x-axis, scale factor -2 and then a translation five units up.

As for the y-intercept, it is (positive) 5.

I hope that is what you meant.

Sorry, I meant scale factor (-1/4)