Answer:
about 1.43 hours.
Step-by-step explanation:
You can use your original equation to find how many minutes it takes to fill up the 309 gallon hot tub.
3.59x=309
x= how many minutes it takes to fill up a certain gallon.
Divide both sides by 3.59 to isolate x and you get x=86.0724234.
That is how many minutes it takes.
The question asks for how many hours, so that divide 86.0724234 by 60 since there are 60 minutes in an hour, and you get 1.43454039 or 1.43 hours.
There is also another way which is called dimensional analysis, but I don't know if you guys learned that yet.
Hope my answer helps!