You can first create an equation to represent the description.
M = 8h + 10
M is the total money made, and h is the hours spent. Going to a house costs $10. This is why it's alone; no matter how many hours is spent at the house, there will always be a $10 charge Every hour spent at that house costs $8. This is why it has a variable with it. This value depends on the time spent.
Plug in the given value ($50) into M and solve for h.