6. a) The mid point of a line segment is (1,-1) whose one end is (-1, -3). Find the other end.

Step-by-step explanation:

mid point = [(a1 + a2)/2 , (b1 + b2)]

(a1,b1) = first point

(a2,b2) = end point

Using all x coordinates

(a1 + a2)/2 = 1

(-1 + a2)/2 = 1

-1 + a2 = 2

a2 = 3

Using all y coordinates

(b1 + b2)/2 = -1

(-3 + b2)/2 = -1

-3 + b2 = -2

b2 = -1

thus end coordinate = (3, -1)

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

the answer is 15% decrease