SOLUTION: The demand for a certain toy is such that no one will purchase it once the price reaches $7. For every $0.02 decreases in price, 1 unit more will be sold. Write the price as a func

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: The demand for a certain toy is such that no one will purchase it once the price reaches $7. For every $0.02 decreases in price, 1 unit more will be sold. Write the price as a func      Log On


   

Question 125385This question is from textbook Intermediate Algebra Review
: The demand for a certain toy is such that no one will purchase it once the price reaches $7. For every $0.02 decreases in price, 1 unit more will be sold. Write the price as a function of the number of units sold.
How many toys would you expect to be sold if the price were set at $4.79? This question is from textbook Intermediate Algebra Review

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
The demand for a certain toy is such that no one will purchase it once the price reaches $7. For every $0.02 decreases in price, 1 unit more will be sold. Write the price as a function of the number of units sold.
:
We need two sets of coordinates to find an equation x = price; y = no. sold
This first set is given x = 7; y = 0
:
Choose the 2nd set of coordinates, x = 6; y = 50, from the statement:
"For every $0.02 decreases in price, 1 unit more will be sold.
:
Find the slope m = %2850+-+0%29%2F%286+-+7%29 = 50%2F%28-1%29 = -50
:
Find the equation using the point/slope formula: y - y1 = m(x - x1)
x1 = 7; y1 = 0; m = -50
y - 0 = -50(x - 7)
y = -50x + 350
:
f(x) = -50x + 350 would be the equation:
:
:
How many toys would you expect to be sold if the price were set at $4.79?
Substitute 4.79 for x
f(4.79) = -50(4.79) + 350
f(4.79) = -239.5 + 350
f(4.79) = 110.5 ~ 110 toys sold at $4.79