$$-x_0 ≤ \sum_{j=1}^n a_{ij}x_j-b_i ≤ x_0 $$ $$ i=1,...m$$ $$\mathrm {min} x_0 $$
(Forgive me if I made any formatting mistakes; I'm not familiar with MathJax)
I know better than to try and use this website as a "homework answers" forum, but I'm honestly not sure where to start. Am I supposed to do something with the Duality Principle?