Mathematics - Algebra - Inequalities - Solving linear inequalities - The Flip Rule

Show: 'If 2 < 5, what happens when we multiply both sides by -1?' 2 becomes -2, 5 becomes -5. Is -2 < -5? NO! -2 > -5. The inequality FLIPPED! Do 3 demonstrations: multiplying/dividing by negative numbers flips the sign. This is THE critical rule that makes inequalities different from equations.