#!/usr/bin/perl
use warnings;
use Math::MatrixReal;

$a = Math::MatrixReal->new_from_rows ([
[1, -2,  3,   4],
[4, -5,  6,   7],
[7,  8, -9,  10],
[8,  9, -9, -11],
]);

print $a,"\n";

my $b = Math::MatrixReal->new_from_cols ([
[17,18,19,20]
]);
print $b,"\n";

print $a->det(),"\n";

$inva = $a->inverse();
print $inva,"\n";

$c = $inva * $b ;

print "solution->\n$c\n";