$ perl -MO=Deparse -ane '$s = ""; foreach (@F) { /(\d+)-(\d+)/ and $2 - $1 >= 30 and $s .= " $1-$2" } print "$F[0]$s\n" if $s'

LINE: while (defined($_ = <ARGV>)) {
    our @F = split(' ', $_, 0);
    $s = '';
    foreach $_ (@F) {
        $s .= " $1-$2" if /(\d+)-(\d+)/ and $2 - $1 >= 30;
    }
    print "$F[0]$s\n" if $s;
}