two letter variables

Dear Experts

I am transcribing an economics textbook and cannot find an example of how to braille the variables in the equation below. I understand single letter variables and how to braille them, but what do I do when the variable is represented by multiple letters? PV stands for present value and FV stands for future value.

FV
PV = ---------
(1+i)n

Would the correct way to braille this be:

(1) [braille],P,V .K ?,F,V/(1+I)^N"#

or

(2) [braille],,PV .K ?,,FV/(1+I)^N"#

Your assistance will be greatly appreciated so I can continue transcribing this book.

Frustrated in Lincoln