Answer:
a. Angel has a greater flat fee
b. Difference = $130
Explanation:
Given
Rose:
![Flat\ Fee = \$50](https://img.qammunity.org/2021/formulas/mathematics/college/doslwopla71tdb0idqea78hjoetfwf43ks.png)
![Rate = \$12](https://img.qammunity.org/2021/formulas/mathematics/college/ctnvxc5jp99270yeln60kgojbs56kose92.png)
Angel
Guests --- Charges
10 -------- $180
15 -------- $255
25 -------- $405
30 -------- $480
Solving (a): Who charges the greater flat fee?
We have that the flat fee of Rose is:
![Flat\ Fee = \$50](https://img.qammunity.org/2021/formulas/mathematics/college/doslwopla71tdb0idqea78hjoetfwf43ks.png)
For Angel, we need to determine the equation of the given table
Start by calculating the slope (m) of the table
![m = (y_2 - y_1)/(x_2 - x_1)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/gjvq8ugonz7wbfcjxpwzkf808xsbjwfyvh.png)
Where x and y represent any two corresponding values of the guests and the charges.
![(x_1,y_1) = (10, 180)](https://img.qammunity.org/2021/formulas/mathematics/college/kgodb9hnrvf6mkckzr2araf5dkk0zjoz1p.png)
![(x_2,y_2) = (30, 480)](https://img.qammunity.org/2021/formulas/mathematics/college/6z5j00pzizd4yofn7wtr0wcaf0bzsaakpo.png)
So:
becomes
![m = (480 - 180)/(30 - 10)](https://img.qammunity.org/2021/formulas/mathematics/college/ie9sl2ipa9y4kaz8yu00bj25x3o7o0rsms.png)
![m = (300)/(20)](https://img.qammunity.org/2021/formulas/mathematics/college/qu7y5riw2c7jbvxf1a7ucygu7l0hilt22i.png)
![m = 15](https://img.qammunity.org/2021/formulas/mathematics/middle-school/j87ivt4qhiz7ahw2u2im58dnx9v0syu2w2.png)
Next, we calculate the equation using:
![y - y_1 = m(x - x_1)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/114ibzuj57ml08mu59z59vjg3t4kik0hxk.png)
Where
![m = 15](https://img.qammunity.org/2021/formulas/mathematics/middle-school/j87ivt4qhiz7ahw2u2im58dnx9v0syu2w2.png)
![(x_1,y_1) = (10, 180)](https://img.qammunity.org/2021/formulas/mathematics/college/kgodb9hnrvf6mkckzr2araf5dkk0zjoz1p.png)
![y - 180 = 15(x - 10)](https://img.qammunity.org/2021/formulas/mathematics/college/1vkbekddr1f8hak58kcf7akxpvunw4md68.png)
![y - 180 = 15x - 150](https://img.qammunity.org/2021/formulas/mathematics/college/6pkk4gunku5xbcdq2v8yvfeus6wllnwe9a.png)
Add 180 to both sides
![y - 180 + 180 = 15x - 150 + 180](https://img.qammunity.org/2021/formulas/mathematics/college/hy34y3ctacj54evekxpidqy6jhp6oj0nbl.png)
![y= 15x + 30](https://img.qammunity.org/2021/formulas/mathematics/college/ytysvp45ioozgx9vre6a9dhuvi9xhkcgy4.png)
From the equation above:
The slope = 15 --- This represents the hourly rate
and
y intercept = 30 --- This represents the flat fee
This is better represented as:
Angel
![Flat\ Fee = \$30](https://img.qammunity.org/2021/formulas/mathematics/college/l7gq0eeloa2l7j3b41r5xdzwhboyqjjcdi.png)
![Rate = \$15](https://img.qammunity.org/2021/formulas/mathematics/college/ivww9z1fiodq6e0brgicsvopc2sykxgqlr.png)
and
Rose:
![Flat\ Fee = \$50](https://img.qammunity.org/2021/formulas/mathematics/college/doslwopla71tdb0idqea78hjoetfwf43ks.png)
![Rate = \$12](https://img.qammunity.org/2021/formulas/mathematics/college/ctnvxc5jp99270yeln60kgojbs56kose92.png)
By comparison, Angel has a greater flat fee
Solving (b): Difference between total charges of 50 guests for both caterers.
For angel, the equation is:
![y= 15x + 30](https://img.qammunity.org/2021/formulas/mathematics/college/ytysvp45ioozgx9vre6a9dhuvi9xhkcgy4.png)
and x = 50.
So:
![y = 15 * 50 + 30](https://img.qammunity.org/2021/formulas/mathematics/college/g45tgh9m8pyemroy2srw9dmt8zq7c06v5c.png)
![y = 750 + 30](https://img.qammunity.org/2021/formulas/mathematics/college/zmovxb3ljx21a29z8bvknanauwlxugh0eh.png)
![y = 780](https://img.qammunity.org/2021/formulas/mathematics/college/jaj8r87o0ss4485ckcibg5472e8qvker0k.png)
For Rose,
First, we need to determine the equation.
![Flat\ Fee = \$50](https://img.qammunity.org/2021/formulas/mathematics/college/doslwopla71tdb0idqea78hjoetfwf43ks.png)
![Rate = \$12](https://img.qammunity.org/2021/formulas/mathematics/college/ctnvxc5jp99270yeln60kgojbs56kose92.png)
The equation is:
![y = Flat\ Fee + Rate * x](https://img.qammunity.org/2021/formulas/mathematics/college/vezwsyaq31fbm5u29uob6vpady92xhn9s1.png)
![y = 50 + 12 * x](https://img.qammunity.org/2021/formulas/mathematics/college/3pddmwfsodaxqs6rgugmvn552zcgrbc0s0.png)
So, the total charges for 50 guests is:
![y = 50 + 12 * 50](https://img.qammunity.org/2021/formulas/mathematics/college/wmr3784rcr3zus8cw1j79ph7y16lgahkwo.png)
![y = 50 + 600](https://img.qammunity.org/2021/formulas/mathematics/college/tuqb9a0j3r88hrtfztvj55rdw9gyi5xsm3.png)
![y = 650](https://img.qammunity.org/2021/formulas/mathematics/college/i95p746xltukqj1r9ivclg870k3tzkkp37.png)
The difference is then calculates as:
![Difference = 780 - 650](https://img.qammunity.org/2021/formulas/mathematics/college/3r42tyy3onje6ckm1a23f104a2azp2sev3.png)
![Difference = \$130](https://img.qammunity.org/2021/formulas/mathematics/college/pvq3ox0c0cj74xaagt22g35kbatg80oahu.png)