Question

A company offers four plans for customers who want to rent DVDs and video games. The cost of the plans can be modeled by a linear function that combines a one time membership fee with a per disc rental rate. The table shows the total cost, including membership fees, for a person who rents 1,2 and 5 discs in a month
Discs rented plan A B C D
1. $14. $12. $10. $12
2. $17. $16. $15. $21
5. $26. $28. $30. $48



Which plan has the smallest one-time membership fee?
Plan A
Plan B
Plan C
Plan D

Answer 1

To solve this, we are going to use the slope formula, and the point slope formula.
Slope formula: $m= \frac{y_{2}-y_{1}}{x_{2}-x_{1}}$
where
$m$ is the slope.
$(x_{1},y_{1})$  are the coordinates of the first point.
$(x_{2},y_{2})$  are the coordinates of the first point.
Point-slope formula: $y-y_{1}=m(x-x_{1})$

Plan A. Coordinates of the first point: (1,14) (number of discs, cost). Coordinates of the second point: (2,17). Lets replace those values in our slope formula:
$m= \frac{y_{2}-y_{1}}{x_{2}-x_{1}}$
$m= \frac{17-14}{2-1}$
$m=3$
Now that we have the slope, we can use the point slope formula:
$y-y_{1}=m(x-x_{1})$
$y-14=3(x-1)$
$y-14=3x-3$
$y=3x+11$
Remember that in a linear equation of the form $y=mx+b$, $m$ is the slope and $b$ is the y-intercept. In our model the y-intercept is the membership fee.
Since $b=11$ in our linear equation, we can conclude that the membership fee is $11

Plan B. Coordinates of the first point (1,12). Coordinates of the second point (2,16).
$m= \frac{y_{2}-y_{1}}{x_{2}-x_{1}}$
$m= \frac{16-12}{2-1}$
$m=4$
$y-y_{1}=m(x-x_{1})$
$y-12=4(x-1)$
$y-12=4x-4$
$y=4x+8$
Membership fee: $8

Plan C. Coordinates of the first point: (1,10). Coordinates of the second point: (2,15).
$m= \frac{y_{2}-y_{1}}{x_{2}-x_{1}}$
$m= \frac{15-10}{2-1}$
$m=5$
$y-y_{1}=m(x-x_{1})$
$y-10=5(x-1)$
$y-10=5x-5$
$y=5x+5$
Membership fee: $5

Part D. Coordinates of the first point: (1,12). Coordinates of the second point (2,21).
$m= \frac{y_{2}-y_{1}}{x_{2}-x_{1}}$
$m= \frac{21-12}{2-1}$
$m=9$
$y-y_{1}=m(x-x_{1})$
$y-12=9(x-1)$
$y-12=9x-9$
$y=9x+3$
Membership fee: $3

We can conclude that the plan that has the smallest one-time membership is Plan D. 

Answer 2

Answer:

Your answer is Plan D

Step-by-step explanation:

HOPE IT HELPS