I'm unable to solve this

MO.9 40.2 Suppose the demand for a particular product is Q = 50 p1.3 where Q is the quantity demanded per month, P is the product's price in dollars, M is average disposable income in dollars, and A is the firm's advertising expenditures, in thousands of dollars. i. What is the advertising elasticity of demand? Interpret what this means to the firm. ii. Suppose the firm expects disposable income to decrease by 10%. If the firm wants to change its advertising enough to offset the effect of the decrease in income (so that its expected quantity sold does not change), how does it need to change its advertising? Be as specific as possible