an investor owns shares of stock A and stock B. The investor owns a total of 200 shares with a total value of $4000.

Question

How many shares of each Stock does the investor own?

Answer 1

Ax + B(200-x) = 4000

where A and B = price of stock A and B

x = amount of stock A, 200-x = amount of stock B

Ax +200B - Bx = 4000

(A-B)x = 4000- 200B = 200(20-B)

x = 200(20-B)/(A-B)

to narrow it down you need more info