I derived P = 85 - Q/2 as the post-tax demand curve. I'm not sure if this is correct because it is different to the answer.
Consider a Market with the following Supply (Qs) and Demand (Qd) curves:
Qd = 200 - 2P Qs = 25
Suppose the government imposes a tax of 15 dollars for each unit sold on buyers. For each unit sold, what is the amount received and kept by producers in the post tax equilibrium?