Precalculas algebra

Question

A clothing business finds there is a linear relationship between the number of shirts,, it can sell and the price,, it can charge per shirt. In particular, historical data shows that  shirts can be sold at a price of $71, while  shirts can be sold at a price of $57. Give a linear equation in the form  that gives the price  they can charge for  shirts.

Answer 1

(7000, 71) and (9000, 57) are the two points on the line.

1. Find slope m = (71-57)/(7000 - 9000) = - 0.007.
2. Choose either point from (7000, 71) and (9000, 57), substitute the numbers into p = -0.007n + b,

you will get b = 120.

3. so, the equation is p = -0.007n + 120.

Answer 2

Use two-point form from Algebra 1:

(y - 2000) / (x - 71) = (9000 - 7000) / (57 - 71)