A company sells boxes of duck calls (d) for $35 and boxes of turkey calls (t) for $45. They make batches of duck calls that fill 6 boxes and batches of turkey calls that fill 8 boxes. The company only has 42 boxes. Which system of equations helps the company plan to make $300?
6d = 42 - 8t
35d + 45t = 300
d = 42 - t
6d + 8t = 42
d = 42 - t
35d + 45t = 300
6d = 42 - 8t
35d - 45t = 300
6d = 42 - 8t
35d + 45t = 300
d = 42 - t
6d + 8t = 42
d = 42 - t
35d + 45t = 300
6d = 42 - 8t
35d - 45t = 300