Word problem, linear function

Question

A toy store learned that when the price for a toy was set at $14.25, exactly 727 toys were sold per week. When the price for the toy dropped to $11.75, exactly 867 toys were sold per week. Let y=T(x) represent the number of toys sold per week when the toy is priced at x dollars. Find the linear function that fits the data.

Answer 1

The slope of the demand line is

 

 (867 - 727)/ ( 11.75 - 14.25) = -56

 

 That is, they lose 56 sales every time the price increases by $1

 

The intercept B = y - mx = 727 - (-56)(14.25) = 1525

 

Demand = D(x) = -56x + 1525

Answer 2

Using the ordered pairs, (14.25, 727) and (11.75, 867), find the slope.  ONce you have the slope, you can than use the point/slope formula for the equation of the line... y-y1 = m(x - x1).  NOte:  remember to use one ordered pair for (x1,y1) and  it doesn't matter which ordered pair you use.