It doesn't have to be taken in reverse order. You could instead examine each $1000 starting from the end of the first year. How long does the first $1000 you invest stay in the bank account and generate interest? Answer: 4 years. A year later when you invest another $1000 dollars, it only stays in the bank for 3 years. And so on. S = 1000(1.09)^4 + 1000(1.09)^3 + 1000(1.09)^2 + 1000(1.09) + 1000 Does that help?
i love you eddie
I can't get it, why is it taken in reverse order?
It doesn't have to be taken in reverse order. You could instead examine each $1000 starting from the end of the first year. How long does the first $1000 you invest stay in the bank account and generate interest? Answer: 4 years. A year later when you invest another $1000 dollars, it only stays in the bank for 3 years. And so on.
S = 1000(1.09)^4 + 1000(1.09)^3 + 1000(1.09)^2 + 1000(1.09) + 1000
Does that help?
@@slothbearanonymous Thank you