STEP 4: Replacing X with (N-1)Q, to find the typical firm's equilibrium quantity, as a function of N , is: QA=90- N-1 QA 2Q=180-(N-1)QA 2QA=180-NQA+QA 2 180 2Q +NQ-Q=180 Q+NQ=180 Q N+1=180 ..QA= (N+1) 180 This implies that the typical firm produces Q= (N+1) in equilibrium