map

1)
$str = "2-5,3-9,1-2,8-1,4-7,5-9,20-3,16-9";
@array=split(/,/, $str);
my @a1= (map
{
($left,$right)=split(/-/,$_);
$left*$right;
}
@array
);
print join(",",@a1),"\n";

2)
@array = (20, 3, 1, 9, 100, 88, 75);
my @new_array = (map { $_*2; } @array);
print join(",", @new_array), "\n";