Robbie is a 20 year old dependent who is a full time student. Robbie has $6,800 in income from wages and $6,000 of interest inco
1 answer:
You might be interested in
Answer:
Explanation:
So, we are looking for a linear equation. As we know Equation of a line has different forms, let´s use slope-intercept form:
Where C is the total cost as a function of t, t is the amount of airtime in minutes, m is the slope and b is the y-intercept
Now, let´s use the data provide in order to find m and b:
(E1)
(E2)
We have a 2X2 system of equations, let´s solve it using elimination method:
Replacing b in (E1) or (E2):
Knowing the slope m and the y-intercept b the linear model that represents the total cost as a function of t is:
You can check the results evaluating t=150 and t=300, the results must be 40 and 55 respectively