SOLUTION: Topic: Sales of widgets I need help in understanding word problems. I need to find an equation using two points in the form of p=mx+b. Especially (x,p) The question is: Suppose

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Topic: Sales of widgets I need help in understanding word problems. I need to find an equation using two points in the form of p=mx+b. Especially (x,p) The question is: Suppose       Log On


   



Question 563509: Topic: Sales of widgets
I need help in understanding word problems. I need to find an equation using two points in the form of p=mx+b. Especially (x,p) The question is: Suppose a market research company finds that at a price of p=$75, they would sell x=10 widgets each month. If they lower the price to p=$40, then more people would buy the widget, and they can expect to sell x=45 widgets in a month.

Answer by htmentor(1343) About Me  (Show Source):
You can put this solution on YOUR website!
p = mx + b
If the p=75, then x=10:
75 = 10m + b [1]
If p=40, then x=45:
40 = 45m + b [2]
Subtract [2] from [1]:
35 = -35m
m = -1
Use one of the two equations above to solve for b:
75 = -10 + b
b = 85
So the equation is p = -x + 85