Question 1041128
{{{P[n]}}} for pounds of the waste after n months.


Quantity produced is quantity stored.
Nine pounds produced per month is a rate;  The independent variable is time, n, in months.  At count of 0 months, already is stored, 16 pounds of waste.  {{{P[0]=16}}}.


{{{P[n]=9n+16}}}, which is the same form as {{{y=mx+b}}}, slope-intercept form for a line.