Question

Part A: Maria rented a coat at $285 for 3 days. If she rents the same coat for 6 days, she has to pay a total rent of $510.

Write an equation in the standard form to represent the total rent (y) that Maria has to pay for renting the coat for x days.

Answer 1

@ganeshie8

Answer 2

i would say y=95x but 95x6 doesn't =510 it equals 570 so idk

Answer 3

@ganeshie8

Answer 4

so (3, 285) and (6, 510) are two points that satisfy the required equation

Answer 5

knw how to write the equation of line given two points ?

Answer 6

um, not really..

Answer 7

remember the slope formula ?

Answer 8

Oh yes! lol hold on

Answer 9

3 = x1 6 = x2
285 = y1 510 = y2

Answer 10

yes ! find the slope, m

Answer 11

510 - 285 = 225
6 - 3 = 3

Answer 12

225/3 = 75

Answer 13

yep ! slope of line, m = 75

Answer 14

so the equation of line will be :

y = mx + b

y = 75x + b

Answer 15

you need to find the value of "b" and plugin above ^^

Answer 16

any idea how to find the value of "b" ? :)

Answer 17

Part B: Write the equation obtained in Part A using function notation.

Answer 18

f(x) = 75x + b

Answer 19

Is this correct?

Answer 20

oh and I found a question and it's actually not a question.. and the person who asked the question is sort of using profanity.. -_-

Answer 21

http://openstudy.com/study#/updates/53d2c1bde4b0f2f7e5e8f4ac

heres the link to it, it needs to be closed because they are just messing around

Answer 22

we're not done with part A, you need to find the value of "b"

Answer 23

oh ok

Answer 24

but idk how to do that

Answer 25

our equation is :

y = 75x + b

and you know that the given two points satisfy this equation, so simply plugin ANY one point and solve b

Answer 26

may be plugin this point

(3, 285)

Answer 27

plug x = 3, y = 285 into ur equation of line

Answer 28

75 * 3 = 225
285 - 225 = 60
60 = b

Answer 29

Yep!
the required equation is ?

Answer 30

y = 75x + 60

Answer 31

yes ! but thats in slope intercept form,
they want equation in standard form

know how to rearrange it into standard form ?

Answer 32

standard form is this :
\[Ax + By=C\]

Answer 33

ok but what is A?

Answer 34

y = 75x + 60

can be rearranged to :

75x - y = -60

Answer 35

thats the standard form ^^

Answer 36

is that clear ?

Answer 37

not really..

Answer 38

y = 75x + 60


we want to change it to "Ax + By = C" form

so subtract 75x both sides, what do u get ?

Answer 39

y = 75x + 60
-75x -75x

Answer 40

you get :

y - 75x = 60

right ?

Answer 41

wait i get it now!, okay thanks! and um, what for part b?

Answer 42

Part B: Write the equation obtained in Part A using function notation.

Answer 43

good :) you're right for part B, its just :

f(x) = 75x + 60

Answer 44

ah okay, but there is one last part.. i know how to do it but i cant explain how to do it

Part C: Describe the steps to graph the equation obtained above on the coordinate axes. Mention the labels on the axes and the intervals.

Answer 45

Find the y-intercept and plot it on the graph.
Use the slope to find a second point and plot it.
Draw the line that connects the two points.

Would this be good?

Answer 46

Even if I am good at something, I can't really explain how to do it...

Answer 47

that looks good, but u need to talk more about specific value of y intercept (60) and the slope (75)

Answer 48

step1 : The y intercept of this function is 60 which can be plotted on y axis : (0. 60)
step2 : using slope (75) the second point can be plotted by going right 1 unit and up 75 units : (1, 135)

step3 : draw a line through the above two points

Answer 49

Okay, thank you so much, you helping be understand this alot better! :)