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WORKED EXAMPLEQd = Qs, so P = 16
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worked exampleEconomics5 min read

Supply and demand: finding equilibrium

Given demand and supply equations, find the price where the market clears.

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supply-and-demand-equilibrium.md
In short

Set quantity demanded equal to quantity supplied and solve for price. Here P = 16 and Q = 68.

The setup

Demand: Qd = 100 − 2P. Supply: Qs = 20 + 3P. Equilibrium is where Qd = Qs.

Solve it

  1. 100 − 2P = 20 + 3P
  2. 80 = 5P
  3. P = 16
  4. Q = 100 − 2(16) = 68

What if the price is wrong?

PriceQdQsResult
108050Shortage of 30
166868Equilibrium
206080Surplus of 20

AI explanations can contain mistakes. Check important answers with your teacher.

AI explanations can contain mistakes. Check important answers with your teacher.

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