15; it represents the one-time sign-up fee
The y-intercept can be found either on the graph where the line intercepts the y-axis, or b in the equation y=mx+b.
It represents the fee because it will be charged even if the number of months (x) is zero. 10 is the monthly fee because it is multiplied by x, the number of months.
The total price she paid for the shirt was $27.03
One advantage is that you don't have to count out your money when you are cashing in. But one con is that people can forge your signature if you give it to them and their dishonest.
A line parallel to x-axis has 0 slope.
