Answer:
-10
Step-by-step explanation:
309
-42 x -7 = 294 + 15 = 309
6x8=48 slices to be sold in 8ths.
2x48= $96
6x4= 24 slices to be sold in 4ths.
24x3=$72
96-72= $24
They will make 24 more dollars if they sell slices in eighths.