# Thread: Simple Algebra - solving for R

1. ## 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 $\displaystyle 4$came from. I understand the rest but I am clueless about that$\displaystyle 4$

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

This came from my math book.

2. 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 $\displaystyle 4$came from. I understand the rest but I am clueless about that$\displaystyle 4$

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

This came from my math book.
~Quacky.

3. If ab = x, then a = x/b OR b = x/a (ab means a times b)