Answer:
20 km rate should 7.76
Step-by-step explanation:
Definitions
The variable rate is the rate for every km.
The fixed rate is what is charged for someone just getting on their bicycle.
Givens
Length of race = 6 km
variable rate = 0.22 / km
fixed rate = x
Total cost = 4.68
Formula
Total cost = fixed rate + variable rate * distance
Solution
4.68 = 6*0.22 + x
4.68 = 1.32 + x Subtract 1.32 from both sides.
4.68 - 1.32 = 1.32 - 1.32 + x Combine
3,36 = x
The fixed rate is 3.36
Before getting the answer to the question asked, we should see if we get the same fixed rate for 24 km
Check
Total Cost = fixed rate + variable rate*distance
Total Cost = 8.64
fixed rate = x
variable rate = 0.22
distance = 24 km
8.64 = x + 0.22 * 24 Combine
8.64 = x + 5,28 Subtract 5.28 from both sides
8.54 - 5,28 = x + 5.28 - 5,28 Combine
3.36 = x which agrees with our first calculation for the fixed rate.
Answer
y = 3.36 + 20*0.22
y = 3.36 + 4.4 Combine
y = 7.76
