The model of the weekly salary of Cherie is:
S(c) = 400 + 0.15c
Where S is her weekly salary, and c is the number of her sales, both in dollars.
S is a linear equation, and the generic linear equation is:
y = m*x + b, where m is the slope of the equation.
If we compare S to the generic linear equation, we see that the slope of S is 0.15. That is, for each sale, Cherie earns 0.15 dollars as commission
