Given that demand for a good X is equal to $q_D=393-2p$ and market supply is $q_S=p/4-12$. Find equilibrium price and quantity, consumer and producer surplus and draw a diagram illustrating the situation. Given that:
a) $T=2q$, every single item sold is taxed.
b) $T=20\% TR$ total revenue is taxed
Obviously i have calculated the equilibrium price and quantity before taxation that is $p=180,q=33$.But i have no idea how to caculate those two values after taxation.