Solving
Multiplication & Division
The process continues to be similar to solving linear equations, except for one main difference, that occurs when multiplying or dividing by a negative number. The Multiplication Property of Inequalities states that the same positive number can be multiplied to both sides of an inequality without changing the solution set. If the same negative number is multiplied on both sides of the inequality the sign must be reversed. Consider 3 > 2. What happens to the inequality when both sides are multiplied by -1? The temptation is to say that the answer will be "-3 > -2". But -3 is not greater than -2; it is indeed smaller. The correct inequality is -3 < -2.
If a > b andc > 0, then ac > bc; and if a < b and c > 0, then ac < bc.
Or
If a>b andc < 0, then ac<bc; and if a<b andc < 0, then ac>bc.
Examples:
7 > 2 7?-4 > 2?-4 -28 < -8