Question

Jessica is selling books during the summer to earn money for college. She earns a commission on each sale but has to pay for her own expenses.

After a month of driving from neighborhood to neighborhood and walking door-to-door, she figures out that her weekly earnings are approximately a linear function of the number of doors she knocks on.

She writes the equation of the function like this: E(x) = 20x - 50, where x is the number of doors she knocks on during the week and E(x) is her earnings for the week in dollars.

What does the slope of Jessica's function represent?
a. For

Answer 1

y = mx +b
the value of m = slope

Answer 2

a. For each additional set of books she sells, her earnings will increase by $20.

b. For each additional door she knocks on, her earnings will increase by $20.

c. For each additional set of books she sells, her earnings will increase by $50.

d. For each additional door she knocks on, her earnings will increase by $50.

Answer 3

which do you think?

Answer 4

i have no idea. im really confused

Answer 5

what does the question tell you X represents?

Answer 6

number of doors

Answer 7

great! so with that - we KNOW the answer is NOT A or C

Answer 8

what is the rate of change (slope) for the # of doors

Answer 9

Here is the equation they provided
E(x) = 20x - 50

Answer 10

20?

Answer 11

yes, so for every extra door there is an increase of $20 bucks...

do you understand now?

Answer 12

yes, thank you :) would you mind if i asked your help on part B to this? I can post it if u want to help

Answer 13

go for it.

Answer 14

She writes the equation of the function like this: E(x) = 7x - 25, where x is the number of doors she knocks on during the week and E(x) is her earnings for the week in dollars.

Which of the following are reasonable interpretations of the y-intercept of Jessica's function?

Check all that apply.

If she does not knock on any doors at all during the week, she will lose $25.

Her expenses are $25 per week.

She can earn $7 per week even if she does not knock on any doors.

She will lose $7 per week if she does not knock on any doors.

Answer 15

Lets look at each one of the "scenarios"

What are your thoughts about the 1st one?

Answer 16

Hint: x=0

Answer 17

the first wouldnt work

Answer 18

no let's think of these as true or false...if x = 0 solve for E(x)

Answer 19

so it would be true

Answer 20

yes

Answer 21

okay - let's look at #2
this logic was explained in the original question - is this statement true or false

Answer 22

false

Answer 23

She earns a commission on each sale but has to pay for her own expenses.
This statement tells you that her expenses are still to be paid, in this case yes they are 25 dollars so this is true also. Do you understand that?

Answer 24

yes

Answer 25

#3 /#4 both of these are asking if x=0 will she lose or make 7 dollars a week
well from the analysis we did already, we know that if x = 0 then she will lose 25 dollars. so they both are.....

Answer 26

false

Answer 27

exactly.

Basically if you understand the components of the equation you can answer any question about it.

Answer 28

okay. thank you!