Linear models (I NEED HELP WITH WORD PROBLEM)

[audball]

HI I am Audrey, I've been trying to figure this word problem out.. and I would appreciate any help, it's due tonight at 11:59 (Pacific time)

In demand and supply problem. y is the number of items the public will buy if the price of the item is x. If the price is $20 per item, then the public wants to buy 519 items. However, if the price is $55 per item then the public would buy only 309 items.
Convert info into two order pairs (Order pair for lower price, and Order pair for the higher price)
and then put it into slope intercept form.

 

[A Zob]

HI I am Audrey, I've been trying to figure this word problem out.. and I would appreciate any help, it's due tonight at 11:59 (Pacific time)

In demand and supply problem. y is the number of items the public will buy if the price of the item is x. If the price is $20 per item, then the public wants to buy 519 items. However, if the price is $55 per item then the public would buy only 309 items.
Convert info into two order pairs (Order pair for lower price, and Order pair for the higher price)
and then put it into slope intercept form.

Hi,
First you need to know what the equation of a line is, the slope intercept form as you call it.

y = mx+b

We already have two sets of numbers of both y and x right so write them out in two different colums for each variable e.g.

x	y
number	number
number	number

you need to make sure that the numbers correspond to each other for this read your word problem if you have any questions ask.

if you reply with a table with the numbers in it i'll go through the next steps.

Zob

 

[stapel]

In demand and supply problem. y is the number of items the public will buy if the price of the item is x. If the price is $20 per item, then the public wants to buy 519 items. However, if the price is $55 per item then the public would buy only 309 items. Convert info into two order pairs (Order pair for lower price, and Order pair for the higher price) and then put it into slope intercept form.

Where are you stuck? You are told that the x-values are the prices and the y-values are the numbers bought. You are then given two pairs of prices and purchases. You are asked to convert these pairs of prices (x-values) and purchases (y-values) into ordered pairs of the form (x, y). So copy the given numbers into the ordered pairs.

You are given that the model for this situation is linear, so the model is y = mx + b. You have been given two points. You have the formula for the slope of a line through two points. Plug your two points into that formula, and find the slope m.

You have points and a slope. You are asked to put these into slope-intercept form, y = mx + b. You have various formulas for straight-line equations. Plug one of the points, along with the slope, into one of the formulas. Solve for "y=", and you'll have your answer.

If you get stuck, please reply showing your work in following the step-by-step instructions. Thank you!