A health insurance plan has a $50 enrollment fee and a copayment of $5 for each doctor visit. The function f(x)=5x+50 gives the cost of x doctor visits. What is the cost for visiting the doctor 3 times?

i leave the calculator work to you.

7. diameter 4 miles, circumference 4π miles

8. radius 0.2 miles, circumference 0.4π miles

[this is a bad problem because the actual radius of a car on the track is less than 0.2 miles so the answer is less than 0.4π miles]

9. radius 6 feet, circumference 12π feet

10. diameter 14 cm, circumference 14π cm

11. diameter 4.8 feet, circumference 4.8π feet