A pool company has learned that, by pricing a newly released noodle at $2, sales will reach 15,000 noodles per day during the summer. Raising the price to $5 will cause the sales to fall to 9,000 noodles per day.

A. Assume the relationship between sale price and number of noodles sold is linear and write an equation describing this relationship

y=

B. Predict the daily sales of noodles if the price is $2.50

y=

linear equation in the form of y = mx +b

you have two unknowns (m and b ) and you have two sets of points - (x,y). all you need to do then is solve for m and b

This post was edited by cialda on Feb 22 2014 06:08pm

y = mx + b

15000 = m * 2 + b
9000 = m * 5 + b

There's two equations so you can solve for the two variables, m and b. Do you know how to solve a system of equations like this?