Using the following equation for the demand for a good or service, calculate the price elasticity of demand (using the point form), cross-price elasticity with good x, and income elasticity.
Q = 8 - 2P + 0.10I + P_x
Q is quantity demanded, P is the product price, and P_x is the price of a related good, and I is income.
Assume that P = $10, I = 100, and P_x = 20.