The extant proofs of
the existence of a rational cross section for a transformation space for a
connected solvable linear algebraic group either use a certain amount of algebraic
curve theory or restrict themselves to the case of a principal space, where
the question is one of galois cohomology, the result being equivalent to the
statement that H1(G,k) = 0 for G a k-solvable linear algebraic group. The
present proof of the general result may be considered more elementary in that
it depends only on the standard facls on fields of rationality of algebraic
sets.