Question

Chris has $100 in his savings account and he adds $20 a month to the account. The total amount can be represented by the linear function T = 20x + 100. His goal is to have a total of $300 in four more months. What should he change in the function to reach this goal?
A)
Change the amount he adds each month to $50.
B)
Change the amount he adds each month to $40.
C)
Change the y-intercept of the linear function to $50.
D)
Change the y-intercepts of the linear function to $200.

Answer 1

What do you think it is?

Answer 2

Well, let's see in 4 months he gets:

T = 20x + 100

T = 20(4) + 100

T = 80 + 100

T = 180

So we should probably change the amount he adds each month, so how much do you think it should be?

Answer 3

40(3) = 120

Answer 4

Let's try changing it to 50.

T = 50x + 100

Plug in 4:

T = 50(4) + 100

What's 50 * 4?

Answer 5

50

Answer 6

Yes, 50 is correct.

Answer 7

50 * 4 = 200

200 + 100 = 300