a)
Let's first find the points that are on y = f(x). This means the y coordinates are 4 and -4, so the x's are -4 and 4, respectively. Because it is on the graph of f(2x), the 2x halves the values, giving a = -2 and b = 2.
b)
Since I can't draw it out, I will tell you how to draw it.
f(2x) will need a half as small x value to have the same effect. Here's an example: f(2 * 3) = f(6). So, we just have to "squish" the graph in towards the linex = 0 so that each x coordinate is half as much, but the y coordinates are the same.
c)
We know that the x's are -4 and 4 (from (a)). So, we set 2x - 8 equal to -4 and 4, getting c = 2 and d = 6.
d)
It has the same coefficient of x, so you can just draw graph b with the same shape but have (2, 4) and (-4, 6) and on the graph in the same spots that (-2, 4) and (2, -4) were in the graph of f(2x).