let x= $4.75 shares 600-x- $5.00 shares 4.75x + 5 (600-x)= 2912.50 distribute and remove ( ) 4.75x +3000-5x= 2912.50 combine like terms -,25x + 3000= 2912.50 subtract 3000 from both sides -.25x= -87.5 divide by -.25 x=350 shares @ $4.75 600-350= 250 shares @ $5,00 hope this helps