please help me solve this proble

Question

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 $73 per share and stock B closed at $81 per share. If Jaafar's stock for these companies was worth $3160, how many shares of each type of stock does he own?

Answer 1

A+B= 40  ----> B = 40 - A

 

73A + 81B = 3160

 

73A + 81(40-A) = 3160

 

73A + 3240 - 81A = 3160

 

-8A + 3240 = 3160

 

-8A = -80

 

A=10

 

10 shares of Stock A and 30 shares of stock B

 

CHECK: 10*73 + 30*81 = 3160