Write a system of equations that can be used to solve the following problem. Then solve the system and determine the answer. Jaafar owns a total of 40 shares of stock, some in stock A and some in stock B. On a particular day, stock A closed at $75 per share and stock B closed at $81 per share. If Jaafar's stock for these companies was worth $3180, how many shares of each type of stock does he own? Let x denote the number of shares of stock A that Jaafar owns. Let y denote the number of shares of stock B that Jaafar owns. Write the equation corresponding to the first sentence of the problem statement ("Jaafar owns a total of 40 shares of stock"). The first equation is