At what average monthly fee would demand equal zero? At what average monthly fee would supply equal zero?

Question

INFORMATION:
Qd=3,000-10 P
Qs= -1,000+ 10 P
Q is the number of buinesses
P is the monthly fee, in dollars
How would Plot the supply and demand curves?
What is the equilibrium price/output level?
Suppose demand icreasese and leads to new demand curve
Qd= 3,500- 10 P
What is the effect on supply?
What are the new equilibrium P and Q?
Suppose new supplies enter the market due to the increase in demand so the new supply curve is Q = -500+10 P.
What are the new equilibrium price and equilibrium quantity?
What would a changes look like on a graph?

Answer 1

1. Qd = 3,000-10 P
0 = 3,000
10 P = 3,000
P = 300

2. Qs = -1,000+ 10 P
0 = -1,000+ 10 P
-10P = -1,000
P = 100

3. Neither Qs nor Qd has any meaning if negative
Scale the Y-axis from 0 -2,000 to 3,000 or 4,000
Neither are negative values of P of interest.
Scale the X-axis from 0 to 300-400
Plot 2 points from each equation and draw a straight line between them.

4. Equilibrium price output level:
Qd = Qs
3,000 - 10P = -1,000 + 10P
4,000 = 20P
P = 200
Qd = Qc = 3000 - 2000 = 1,000

5. Supply would increase to meet demand.

6. New equilibrium point:
Qd = Qs
3,500 - 10P = -1,000 + 10P
4,500 = 20P
P = 225
Qd = Qc = 3500 - 2250 = 1,250

7. New equilibrium from new supplies:
Qd = Qs
3,500 - 10P = -500 + 10P
3,000 = 20P
P = 150
Qd = Qc = 3000 - 500 = 2,500

Plot new lines on your graph using different colors for the new conditions.

Answer 2

Mine does, but not directly. What I do is sell Information Products very cheap and then send the buyers a thank you with an invite to be on my list if I give them a bonus. Then I can follow up with more sales off Ebay.