If </= mean greater than or equal to then (by simple algebra): X4 – X4 </= 0.1X1 + 0.1X2 + 0.1X3 –X4 0 </= 0.1X1 + 0.1X2 + 0.1X3 – X4 or 0.1X1 + 0.1X2 + 0.1X3 – X4 >/= 0

Yes,Mr. Engineer, you got it right. You can add at both sides of the inequality. The only thing you gotta emeber is that if you multiply both sides of the inequality by a negative number then the sign of the inequality (less than or greater than ) changes. Everything else is handled like a normal algebraic equation. Greetings