Question

A(t)=I(1-r)^t just need to know wht all the letters represent

Answer 1

Given the expression:

$A(t)=l(1-r)^t$

We have that A(t) is a dependent variable. We call it this way because its value depends on the value of the resulting expression when t is evaluated. Therefore, 't' is an independent variable.

The letter 'l' can be a constant, just like 1.