A truck can be rented from Company A for $80 a day plus $0.50 per mile. Company B charges $60 a day plus $0.70 per mile to rent the same truck. Find the number of miles in a day at which the rental costs for Company A and Company B are the same.

100 miles

Step-by-step explanation:

Company A’s charges can represented by the equation: 0.50m+80

Company B’s charges can represented by the equation: 0.70m+60

To find when the cost is the same for both companies, I will set the two equations equal to each other.

0.50m+80=0.70m+60

-0.50m -0.50m

80=0.20m+60

-60 -60

20=0.20m. Divide both sides by 0.20

100=m

So after 100 miles, the cost for both companies are the same.

f(x) has value 150 at x= 0

and 0 at x= 3

so d(f(x))/dt = slope = -150/3 = -50