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Solving for Variable

Date: 2/7/96 at 22:19:14
From: Anonymous
Subject: Solving for Variable

If;  Pt = PV(R) / (1-(1+R)EXP(-N)) is used to determine a Pt (monthly 
payment), if PV (present value), R (rate) and N (term) are known, how 
is this simplified to solve for R?

Date: 7/22/96 at 22:16:2
From: Doctor Jerry
Subject: Re: Solving for Variable

I'd like to change your notation a little.  

Let P stand for Pt, V for PV, and leave the remaining variables the 
same.  Your equation is (I think)


Start by multiplying both sides of this equation by (1-(1+R)e^(-N)).  
This gives


Expand the left side to get


Move all terms involving R to the left and all other terms to the 


Factor R from the two terms on the left and change some signs




or, multiplying top and bottom of the fraction on the right by e^N,


I hope this is clear.

-Doctor Jerry,  The Math Forum
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Associated Topics:
High School Basic Algebra

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