On Tue, Feb 26, 2008 at 11:58 AM, Todd Benson <caduceass / gmail.com> wrote:
>
> On Tue, Feb 26, 2008 at 2:29 AM,  <grandmabeckie / msn.com> wrote:
>  > I am try to help my daughter:
>  >  Problem
>  >
>  >  father is 4 times older then his daughter.
>  >  in 6 years he will be 3 times older what is the answer and how did you
>  >  reach it.
>  >  Thanks, a mom in CA
>
>  Here's a matrix solution...
>
>  require 'matrix'
>  coefficient_matrix = Matrix[[1, -4], [1, -3]]
>  solution_vector = [[0], [12]]

Oops, that line was supposed to be...

solution_vector = Matrix[[0], [12]]

Todd