<PRE><B>Question 146117</B>
The function S=5000 +200x and D= 9500 - 100x express the supply S and the demand D respectively, for a popular CD brand as a function of its price x in dollars.
Graph the functions on the same coordinate system.
:
Graph both for x = 5 and x = 25; let S and D = y
S = 5000 + 200x; (purple)
 x | y
-------
 5 |6000
25 |1000
and
D = 9500 - 100x; (green)
 x | y
-------
 5 |9000
25 |7000
:
Graph should look like this:
{{{ graph( 300, 200, -20, 80, -2000, 12000, 200x+5000, -100x+9500) }}} 
:
What happens to the supply as price increases?
Supply goes up (purple)
:
What happens to demand as price increases?
Demand goes down (green)
:
The price at which supply and demand are equal is called equilibrium price. What is the equalibrium price?
:
Where the two graphs intersect, x = 15; is the equilibrium price</PRE>