Suppose a one-year subscription to a magazine costs $12.99 and a three-year subscription costs $25.98. The cost and length of a subscription are related. Write a slope-intercept equation to model the cost of a subscription for any period of time.

Respuesta :

Answer:

[tex]y = 6.495x + 6.495[/tex]

Step-by-step explanation:

Represent years with x and cost with y.

So, we have:

[tex](x_1,y_1)=(1,12.99)[/tex]

[tex](x_2,y_2)=(3,25.98)[/tex]

Required

Determine the slope intercept equation

First, we calculate the slope (m)

[tex]m = \frac{y_2 - y_1}{x_2 - x_1}[/tex]

[tex]m = \frac{25.98 - 12.99}{3 - 1}[/tex]

[tex]m = \frac{12.99}{2}[/tex]

[tex]m = 6.495[/tex]

The equation is then calculated as:

[tex]y - y_1 = m(x - x_1)[/tex]

Where

[tex]m = 6.495[/tex]

[tex](x_1,y_1)=(1,12.99)[/tex]

[tex]y - 12.99 = 6.495(x - 1)[/tex]

[tex]y - 12.99 = 6.495x - 6.495[/tex]

Make y the subject

[tex]y = 6.495x - 6.495 + 12.99[/tex]

[tex]y = 6.495x + 6.495[/tex]