Answer:
a. 
b. 
Step-by-step explanation:
a. Radius of semicircle (r) = r
Diameter of semicircle (d) = 2r
Length of rectangle (l) = 2*diameter of semicircle = 2*2r = 4r
Distance around the track (p) = circumference of circle + 2(l)
Note: the two semicircles of the track = 1 full circle
Circumference of full circle = πd = π*2r = 2πr
Distance around the track:
p = 2πr + 2(4r)
p = 2πr + 8r
b. Rewriting the formula to make radius, r, the subject of the formula in terms of distance around the track.

Factor out r

Divide both sides by (2π + 8)



9 or -9 because if -9 is squared the negative cancels
Use the formula for the volume of a cylinder to work out how much wax you need to make one candle.
π×5²×15 = 375π
Then divide the amount of wax you have by the amount of wax you need to produce one candle to work out how many candles you can make.
4500 ÷ 375π = 3.82
However, you can't produce 82% of a candle, so you have to round down to 3 candles.
Answer:
f^-1(x) = (x+20) / 12
Step-by-step explanation:
f(x) = 4(3x-5)
Let y be the image of f.
y = 4(3x-5)
y = 12x-20
y+20 = 12x
x = (y+20) / 12
f^-1(y) = (y+20) / 12, so
f^-1(x) = (x+20) / 12