generate a valid equation using specified operators
Perl, 129 160 151 chars

sub a{my($s,$t,$o)=splice@_,0,3;@_?map{a("$s $_","$t$o$_",@_)}1..9:
$o-eval$t||$o-eval"use integer;$t"||exit say$s}a"","","",split$",&lt;&gt;;say"NO SOLUTION"


Fun with recursion. The program exits upon finding the first valid tuple.

The eval has to be done twice, in and out of integer-only mode, in order to avoid invalid solutions like that given in example 5 in the description.