When is it necessary to change the symbol of an inequality?

Answer by  cubedbee (155)

If you are multiplying or dividing both sides of an inequality by a negative number, then the symbol of the inequality needs to be reversed. In all other cases, the symbol stays the same.

Answer by  esteban (1334)

When you multiply or divide by a negative number, the inequality symbol changes. For example in -3x > 15, after we divide by -3, we have x < -5. Also, if you want to change the order of the inequality, as in y < 4 changed to 4 > y.