SOLUTION: The consumers will demand 20 units when the price of a product is $69, and 33 units when the price is $50. Find the demand function (express thr price in terms of the quantity ),

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: The consumers will demand 20 units when the price of a product is $69, and 33 units when the price is $50. Find the demand function (express thr price in terms of the quantity ),       Log On


   

Question 403382: The consumers will demand 20 units when the price of a product is $69, and 33 units when the price is $50. Find the demand function (express thr price in terms of the quantity ), assuming it is linear.
Answer by sofiyac(983) About Me  (Show Source):
You can put this solution on YOUR website!
(20,69)
(33,50)
So x is units and y is price
m=%28y2-y1%29%2F%28x2-x1%29=%2850-69%29%2F%2833-20%29=%28-19%2F13%29
Use the point slope formula and plug in the slope and one of the points given
y-y1=m%28x-x1%29
y-69=%28-19%2F13%29%28x-20%29
y-69=-19x%2F13%2B380%2F13 add 69 to each side
y=-19x%2F13%2B380%2F13%2B69 simplify
y=-19x%2F13%2B380%2F13%2B897%2F13
y=-19x%2F13%2B%28380%2B897%29%2F13
y=-19x%2F13%2B1277%2F13
+graph%28+300%2C+200%2C+-50%2C+100%2C+-150%2C+150%2C+-19x%2F13%2B1277%2F13%29+