Final answer:
Sam must work at least 9 hours trimming trees to earn at least $47, based on his hourly charge of $6 and a one-time equipment fee of $7.
Step-by-step explanation:
Sam wants to earn at least $47 trimming trees. He charges $6 per hour and pays $7 in equipment fees. To determine the possible numbers of hours Sam could work, we need to set up an inequality.
Let t represent the number of hours Sam will work. The total amount Sam earns is then $6 times the number of hours worked (t), minus the $7 equipment fee. Sam wants to earn at least $47, so we have the following inequality:
6t - 7 ≥ 47
To solve for t, we first add 7 to both sides of the inequality:
6t - 7 + 7 ≥ 47 + 7
6t ≥ 54
Now, we divide both sides by 6 to isolate t:
t ≥ 54 / 6
t ≥ 9
So, Sam needs to work at least 9 hours trimming trees to earn at least $47.