If r is a real zero of even multiplicity of a function f(x), then the graph of f
the axis at r=r.

The problems states that his deductible is $2500 so he will get $500  ($3000- 2500) from the insurance company.
If this accident happens the first month he has insurance he will also have spent $50 so he will have $450
You did not say how long he has been paying his premiums but I am going to assume it has been a year or 12 months @ $50 or $600.   In that case we do $500-600 = $-100 and he will have to pay $100
I don't care for the question because premiums get paid whether you make a claim or not and should not be considered in how much he will get if he makes a claim.