change sides, change signs(redirected from change sides change signs)
change sides, change signs
A mnemonic used in mathematics to remember that when adding or subtracting a value from one side of an equation, you must apply the opposite value to the other side. Well, here's the problem. You tried to solve the equation by subtracting X from both sides. If you're subtracting X from one side, you must add X to the other side. Remember—change sides, change signs!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.