equation 1: 50c +30d =550
equation 2: 44c + 36d=532
multiply equation 1 by 1.2 so d's equal
50c + 30d =550 x 1.2 = 60c +36d =660
subtract equation 2 from equation 1
60c +36d =660 - 44c + 36d=532 = 16c=128
c=128/16 =8
chickens cost $8
now plug that into 1st equation to solve for d
50(8) + 30d = 550
400 + 30d = 550
30d=150
d=150/30 =5
ducks cost $5