Hi, i would like some help on how to solve the following equation system:

$\displaystyle \begin{array}{lcr}3x+10y+0.5k = 100 \\

x+y+k = 100 \end{array}$

I know that you normally reduce down a system like this to only two variables

For equations on the form $\displaystyle ax+by=c$ there is a formula:

$\displaystyle (cu-bn,cv+an), n \in \mathbb{Z}$

But how do you solve this when you have to deal with floating point numbers?