Answer:

Step-by-step explanation:
Before we find x, we need to set up this triangle a little more. We need to find the triangle's altitude before we can solve for x. We will use the heartbeat method to find the altitude.
Let altitude = y; solve for y:




Now that we know the altitude, we can use the Pythagorean Theorem to find the hypotenuse (x).





Since c and x are the same; c is just the hypotenuse in the Pythagorean Theorem.

Answer:c(d) = 5 + (0.75*d)
Step-by-step :
In this equation the cost (c) of the distance traveled (d) has a base rate of 5, and increases by .75 for every mile traveled (d)
S is slope
S= rise/run
S1=3/12=1/4
S2=2/16=1/8
S3=5/15=1/3
S4=4/20=1/5
Deepest slope S3 aka C