Linear Programming: Shares and Dividends

Hi all,

I have two eqns which are related to stock and dividends which i think LP could help to solve( .. i hope).

5.5x + 2.5y = theta

67.00x + 28y = 200 000

x>0, y>0, theta>0

I derived the above two eqns from this:

Stock A is @ 67.00

Stock B is @ 28.00

Stock A pays 5.5 dollars per share annually

Stock B pays 2.5 dollars per share annually.

(ie. if i get 1 x 67.00 and 0 x 28.00, that year i'll get $5.50)

My question is how to derive the set of {x,y} that would yield a max theta?

Million thanks,

Gary