solve problem 7 and 8

Problem 7 Assume that a CONSUMER has an income of $100. The price of good Y is $10. The consumer has a Utility function given by U(X, Y) - xy. a) What should be the price of Good X, or (Px), so the consumer decides to buy 10 units of X? Please use equations to solve this problem. Problem 8 Assume that the price of good Y is $10. The price of good X is $10. The consumer has a Utility function given by U(X,Y) - xy. a) What should be the income (M) so the consumer can achieve a utility of 100 or U-100? Please use equations to solve this