Abstract: The aim of this work is to find the solvable extensions of the given series
of nilpotent Lie algebras of even dimension. The first part focuses on the
simplest case, that is six-dimensional one. The second part generalizes the
results of the former to arbitrary even dimension of the chosen algebra. One
of the aims is the contribution towards the classification of solvable Lie
algebras of higher dimensions, the other is to reveal at least a little some
properties of solvable Lie algebras in general.