Answer:
Supplier A is cheaper than supplier B.
Explanation:
Supplier A sells grain for $5.25 per bushel plus a delivery fee of $3 per bushel.
Supplier B sells the grain for $6.50 per bushel plus a flat delivery fee of $1,500 each week.
When 500 bushels are bought from supplier A.

=>
dollars
When 500 bushels are bought from supplier B.

=>
dollars
Therefore, Supplier A is cheaper than supplier B.