# Math Help - Equation help - LCD with variables

1. ## Equation help - LCD with variables

Hi there,

Many thanks in advance for the help.

Here is the equation I am struggling to solve:

110 = 1/(1+r) x 32.1/r

How I solve for "r", or perhaps find an LCD with these denominators?

Thanks so much,
Naldo

2. ## Re: Equation help - LCD with variables

110 = 1/(1+r) x 32.1/r
assuming the "x" meant multiplication ...

$110 = \frac{32.1}{r(r+1)}$

$r(r+1) = \frac{32.1}{110}$

$r^2 + r - \frac{32.1}{110} = 0$

recommend using the quadratic formula ...

3. ## Re: Equation help - LCD with variables

Thank you so much for the help!

Best!