At Finky Feed Store, Gerby purchased 7 pounds of cracked corn, 3 pounds of sunflower seed, and 8 pounds of mixed bird seed for $31.00. Michael purchased
5 pounds of cracked corn, 4 pounds of sunflower seed, and 10 pounds of mixed
bird seed for $32.75. Jayleen purchased 4 pounds of sunflower seed and 12
pounds of mixed bird seed for $27.00.
If c represents cracked corn, s represents sunflower seeds, and b represents bird
seed, which of the systems of equations below can be used to determine the
price per pound of cracked corn, sunflower seed, and bird seed?