# Simple Algebra - solving for R

• January 18th 2011, 11:14 AM
killasnake
Simple Algebra - solving for R
Its been awhile since I took a math class, I was reviewing this question but I do not understand where the $4$came from. I understand the rest but I am clueless about that $4$

$4000=1000$ x $(1+r)^5$
$(1+r)^5=4$
$(1+r)=4.0$^(1/5) $=1.32$
$r=.32$

This came from my math book.
• January 18th 2011, 11:25 AM
Quacky
Quote:

Originally Posted by killasnake
Its been awhile since I took a math class, I was reviewing this question but I do not understand where the $4$came from. I understand the rest but I am clueless about that $4$

$4000=1000$ x $(1+r)^5$
Divide both sides of the equation by 1000.
$(1+r)^5=4$
$(1+r)=4.0$^(1/5) $=1.32$
$r=.32$

This came from my math book.

~Quacky.
• January 18th 2011, 12:29 PM
Wilmer
If ab = x, then a = x/b OR b = x/a (ab means a times b)