In 1987, a 30-second superbowl ad cost $40,000. in 2000, a 30-second commercial cost 1,800,000. what was the percent of change in the cost of a commercial?

The percent change is a 450% increase in the cost of advertisements.

To find the equation of a line that is parallel to your original equation and goes through a certain point on a graph, here's what you need to know:
First you need to find the slope of your original equation.
To do that, you need to convert it to slope intercept form (y = mx+b).
Add the x over, and then divide everything by 5 to get the y by itself.
Here's what that would look like (without the small steps that I mentioned):
-x + 5y = 25
5y = x + 25
y = 1/5x + 5

That's the original equation rewritten in slope intercept form.
The m represents the slope, so this equation's slope is 1/5.

Because you are given a point, and now you have a slope, the best and easiest route is using point slope form.
I've seen different versions of the equation base but I prefer y - y(sub1) = m(x - x(sub1))
But since I can't use subscripts in this, I'll use the one with h and k. The h is the x value of the point, and the k is the y value.
(h,k)
Then just substitute the values in and solve for y.
y - k = m(x - h)
y + 5 = 1/5(x + 5)
y + 5 = 1/5x + 1
y = 1/5x - 4

Your final answer is
y = 1/5x - 4
You can double check by using a graph. If the slopes are the same, the lines should be parallel.

I hope that helps. If anything didn't make sense, feel free to ask me.