As I said before: Not enough information...

It seems as if your formular is something like this (untested code of course):

my @sign=( .... ); # Some combination of -1, 0 1
my @sum= map { $sign[$i] * $VAR1[$i] } (0..$#VAR1);
print eval join ' + ', @sum;
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Now you "only" need to get the correct combination of -1, 0 and 1 for @sign, which is a "simple" combinational task but will be very lengthy...