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2.4 Skill Prep Assignment for Quadratic Inequalities….

Find and mark the value on the number line that, when substituted in for the variable, will cause the expression to equal zero. Then determine if values to the left and right of this number will cause the expression to be positive or negative and label the number line accordingly.

Example 1.       Given .

                          when .  Mark this number on the number line.

                           Notice, all values to the right of -3 will cause the expression to be positive

                           when substituted in for x and all values to the left of -3 will cause the

                           expression to be negative.                       

Example 2.      Given .

                             when  m = -1.  Mark this number on the number line.

                           Notice, all values to the right of -1 will cause the expression to be negative

                           this time when substituted in for m and all values to the left of -1 will

                           cause the expression to be positive.