Turning your code into something I can run gives:

use strict;
use warnings;

my $leftEq         = -8;
my $rightEq        = -8;
my $factor         = 0.5;
my $leftStorDelta  = -15;
my $rightStorDelta = -15;

print "LEQ/REQ: $leftEq $rightEq\n";
($leftEq, $rightEq) =
    ($leftEq + $leftStorDelta * $factor, $rightEq + $rightStorDelta * 
+$factor);
print "Fct: $factor Delt: $leftStorDelta $rightStorDelta\n";
print "Post-LEQ/REQ: $leftEq $rightEq\n\n";

printf "%0.2f, %0.2f\n", 1.23, 1.345;
[download]

Prints:

LEQ/REQ: -8 -8
Fct: 0.5 Delt: -15 -15
Post-LEQ/REQ: -15.5 -15.5

1.23, 1.35
[download]

with a bonus line that shows printf in use.