X Given the demand equation p + = 20, where p represents the price in dollars and x the number of units, determine the elasticity of demand, E(p), when p = $5, and indicate whether the demand is elastic, inelastic, or unitary at that value. O E(5) = 3 ;and the demand is elastic O E(5) = 3; and the demand is inelastic O E(5) = 1; and the demand is unitary O E(5) = 3; and the demand is elastic O E(5) = ; and the demand is inelastic