Solve clearly

Suppose we have the following equations: Demand Curve: Qp = -1,450 - 25Px + 12.5Py + .2Inc Supply Curve: Qs =-100 + 75Px - 25Py - 12.5P, + 10R Where Q = quantity Px = price of our good X Inc = income = $8,000 R = rainfall = 20 Py = price of product Y = $5 Pz = price of product Z = $8 a. Calculate equilibrium price and quantity. b. Is Good X a normal good or inferior good? Use/calculate elasticities to answer this, and explain. c. Are Goods Y and Z substitutes or complements to our good X? Use/calculate elasticities to answer this, and explain. d. Why is it easiest (in fact, necessary) to use simple calculus to calculate elasticities