Step by step please

The consumer demand equation for tissues is given by q = 10,404 -204 p +p-, where p is the price per case of tissues and q is the demand in weekly sales. Determine the price elasticity of demand E when the price is set at $28. (Round your answer to three decimal places. ) E = Interpret your answer. When the price is set at $28, the demand is going ? by % per 1% increase in price. At that price level, the demand is ----Select---- If they raise prices, revenue will ----Select-... v