Answer:
r = A/(Pt) -1
Step-by-step explanation:
To solve for r, we undo the operations done to it. r is ...
- added to 1
- and the sum multiplied by Pt
We undo these operations in reverse order, so we first divide by Pt:
... A/(Pt) = 1 + r
Then, we subtract 1:
... A/(Pt) -1 = r
