Answer and Step-by-step explanation: Suppose remaining credit is y and time in minutes is x. To determine a value of y corresponding to a value of x, first find the equation for the function.
Since the function is linear, the equation is of the form: y = mx + b. To determine it:
1) Find slope, or inclination, of the line:
slope (m) = [tex]\frac{y_{b}-y_{a}}{x_{b}-x_{a}}[/tex]
where x's and y's are points of the function.
2) Determine the y-intercept, or b: Use a point of the function, replace them at the equation, y = mx + b, and find b.
3) The equation will be: y = mx + b
With the equation, replace x for the minutes the question is asking and calculate to find the remaining credit.
Th result will be a pair (x,y)
