How do you solve b/3-1=4?

Alright! In order to solve this, you have to isolate your variable, which is b. To do that you'd first have to add one to both sides in order for you to be left with:

[b/3 = 5]

Since 3 is in the denominator, you multiply both sides by 3 in order to get rid of it. In the end you get

[b = 15]

The answer is 15.