We say that a fraction is in "simplest form" if it can no longer be simplified. This means that there are no more factors that can be divided out of the numerator and denominator.
If a numerator and denominator have a GCF of 1, this means the greatest thing that divides both of them is 1. This means that there are no more factors we can divide by, which means there is no more simplification to do; this is simplest form.
i believe this is right. 115 is what he has and what he spends has to be less than that and x is how many lines so solve for x to find how many lines he can have