Please show workings and calculations

Suppose demand and supply curves in the vitamin supplements market have the following functional forms:

QD = 112-4PandQS = 6P-18

where P is measured in dollars per bottle of vitamins.

Part (a): Suppose vitamins are initially priced at $18. Identify whether there is excess supply or excess demand, and calculate the level of excess supply or excess demand that exists in the market.

Part (b): Based on your answer to part (a), describe how the price must adjust.

Part (c): Calculate the equilibrium price and the bottles of vitamin supplement sold.