SOLUTION: I have been working on this question for hours and my work doesn't add up right. Can you please show me how i would work this problem out. Free market. The equations S = 5000

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Question 246261: I have been working on this question for hours and my work doesn't add up right. Can you please show me how i would work this problem out.
Free market. The equations S = 5000 + 200x and D = 9500 - 100x express the supply S and the demand D, respectively, for a popular compact disc brand in terms of its price x (in dollars).
a) Graph the equations of the same coordinate system.
b) What happens to the supply as the price increases?
c) What happens to the demand as the price increases?

Answer by Theo(13342) (Show Source):
You can put this solution on YOUR website!
S = 5000 + 200x
D = 9500 - 100x

x is the price in dollars.
S is the supply
D is the demand

Looks like the supply goes up as the price goes up.

Looks like the demand goes down as the price goes up.

The graph of these equations would look like the following:

a) Graph the equations of the same coordinate system.

b) What happens to the supply as the price increases?

The supply goes up.

c) What happens to the demand as the price increases?

The demand goes down.

There's an equilibrium point where the supply is the same as the demand.

That's where the graph of the two equations intersect.

You solve for that point by making the two equations equal to each other.

You get:

5000 + 200x = 9500 - 100x

add 100x to both sides of this equation and subtract 5000 from both sides of this equation to get:

200x + 100x = 9500 - 5000

combine like terms to get:

300x = 4500

divide both sides of this equation by 300 to get:

x = 4500/300 = 45/3 = 15

the graph confirms that.