Tony and Ricky spend a certain amount of money from their accounts each week at a pet shelter. The table shows the relationship
between the amount of money (y) remaining in Tony's account and the number of weeks (x): Function 1: Number of Weeks (x) Amount Remaining (dollars) (y) 1 30 2 24 3 18 4 12 The equation shows the relationship between the amount of money, y, remaining in Ricky's account and the number of weeks, x: Function 2: y = –7x + 30 Which statement states and explains which function shows a greater rate of change?
Number of Weeks (x) Amount Remaining (dollars) (y)
1 30 2 24 3 18 4
12
You find the rate of weekley rate of change by calculating the difference of the amont remaing between two weeks:
24 - 30 = - 6
18 - 24 = - 6
12 - 18 = - 6
As you see the rate of change is constant: - 6 dollars per week.
The equation shows the relationship between the amount of money, y,
remaining in Ricky's account and the number of weeks, x:
Function 2: y =
–7x + 30 Which statement states and explains which function shows a
greater rate of change?
The rate of change is the slope of the linear function, and this is the coefficient of the independent variable, x. Then the rate of change is - 7 dollar per week. Now you know that the two rates are constant and that the second function shows a steeper decreasing.
