The demand for Wanderlust Travel Services is estimated to be:
Qdx = 22,000 - 2.5Px + 4Py - 1M - 1.5Ax
Ax represents the amount of advertising spent on X and M represents consumer income. The other variables have their usual interpretations. Suppose the price of good X is $450, Good Y sells for $40, the company utilizes 3,000 units of advertising and consumer income is $20,000.
Calculate the own price elasticity of demand at this values of prices, income, and advertising.