Using a linear function, we have that:
a) The fixed cost is of $10.
b) The equation is: C = 10 + 12d.
c) The cost of an 18 km trip is $226.
d) The distance traveled is of 20 km.
<h3>What is a linear function?</h3>
A linear function is modeled by:
y = mx + b
In which:
- m is the slope, which is the rate of change, that is, by how much y changes when x changes by 1.
- b is the y-intercept, which is the value of y when x = 0, and can also be interpreted as the initial value of the function.
For this problem, the slope is of m = 12. When d = 5, C(d) = 70, hence we find the fixed cost as follows:
C(d) = 12d + b
70 = 60 + b
b = 10.
Hence the equation is:
C(d) = 12d + 10.
For a trip of 18 km, d = 18, hence the cost is:
C(12) = 12 x 18 + 10 = $226.
When the cost is of $250, the distance is found as follows:
250 = 12d + 10
12d = 240
d = 240/12
d = 20 km.
More can be learned about linear functions at brainly.com/question/24808124
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Answer:
$1.25
Step-by-step explanation:
This can best be determined using a set of linear equations that are solved simultaneously.
This pair of linear equations may be solved simultaneously by using the elimination method. This will involve ensuring that the coefficient of one of the unknown variables is the same in both equations.
Let the cost of a cookie be c, cost of a doughnut be d and that of a box of doughnut hole be h then if cost of 4 cookies, 6 doughnuts, and 3 boxes of doughnut holes is $8.15, we have
4a + 6d + 3h = 8.15
and the cost of 2 cookies, 3 doughnuts, and 4 boxes of doughnuts holes is $7.20 then
2a + 3d + 4h = 7.20
Dividing the first by 2
2a + 3d + 1.5h = 4.075
subtracting from the second equation
2.5h = 3.125
h = 1.25
The cost of a box of doughnut holes is $1.25
Answer:Jack is 9 and the father is 43
