Math test question I just did.

[davie08]

Homework Statement

find the equilibrium value of q and the market clearing price p for each of the supply and demand functions. sketch the graph.
p= 8q/q+50, q+50 , q> 0 (supply)

p=3q+630/q+30, q>0 (demand)

Homework Equations

3. The Attempt at a Solution [/b

okay so I worked this out on the test to be:

q=150 and p=$6

I know how to do the graph. but this same question is in my book where a lot of answers have been wrong and it says q=92.8 and p=5.20.

So I just want to have this answer confirmed thanks.

 

[Mark44]

Homework Statement

find the equilibrium value of q and the market clearing price p for each of the supply and demand functions. sketch the graph.



p= 8q/q+50, q+50 , q> 0 (supply)

p=3q+630/q+30, q>0 (demand)

Is your supply equation p = 8q/(q + 50)? If so, USE PARENTHESES! What you wrote simplifies to p = 8 + 50 = 58, and I don't think that's what you meant.
Also, why does q + 50 appear twice?

In your demand equation, is it p = 3q + (630/q) + 30?
If not, USE PARENTHESES so that we can tell what you mean.

Homework Equations

3. The Attempt at a Solution [/b

okay so I worked this out on the test to be:

q=150 and p=$6

I know how to do the graph. but this same question is in my book where a lot of answers have been wrong and it says q=92.8 and p=5.20.

So I just want to have this answer confirmed thanks.

 

[davie08]

Is your supply equation p = 8q/(q + 50)? If so, USE PARENTHESES! What you wrote simplifies to p = 8 + 50 = 58, and I don't think that's what you meant.
Also, why does q + 50 appear twice?

In your demand equation, is it p = 3q + (630/q) + 30?
If not, USE PARENTHESES so that we can tell what you mean.

sorry its p=8q/(q+50) for supply

and p=(3q+630)/(q+30) for demand

 

[Mark44]

Much better.

I get q = 150, too.

Good job!

 

[davie08]

thanks that's a relief I feel like I should definitely be over 80% for this test, and I'll need that because the next unit is everyone's favorite derivatives.