Mike bought 8 shares of stock for $57.50 each, hoping that the value would increase. When he sold the shares it was only for $42.75 per share. Which describes Mikes net profit

Bought 8 shares at 57.50 each = 460 total
Sold shares at 42.75 each = 342

Net profit = revenue - expense

= 342 - 460
= -118

Mike has a net loss of $118 because he sold the shares at a lower price than what he bought them for.