  This contribution describes relationship between fractions, projective
representation, duality, linear algebra and geometry. Many problems lead to a
system of linear equations. This paper presents equivalence of the
Cross-product operation and solution of a system of linear equations Ax=0 or
Ax=b using projective space representation and homogeneous coordinates. It
leads to conclusion that division operation is not required for a solution of a
system of linear equations, if the projective representation and homogeneous
coordinates are used. An efficient solution on CPU and GPU based architectures
is presented with an application to barycentric coordinates computation as
well.
