To answer this you would first start with a representation of the situation. See the attached step 1. Use this inequality to find the number of bagels he can get by solving it.
See step two in the attached picture for the work necessary to solve this.
The answer is not a whole number, so you have to round down to make it a whole number of bagels.
The answer is he could by seven or less bagels. You should substitute this in to prove it works.