Question 753611
{{{L=15s+120}}} means that {{{L}}} is a linear function of {{{s}}}.
The slope of the line is {{{15}}}.
It means that for each unit increase in {{{s}}}, {{{L}}} increases by 15 units.
I suspect there was more to the problem.
Not knowing what {{{L}}} and {{{s}}} stand for, I cannot say more about what the slope represents.