2­9 Compound Inequalities.notebook
October 18, 2016
2­9 Compound Inequalities
A compound inequality consists of two distinct inequalities joined by the word and or the word or
The graph of a compound inequality with the word and contains the overlap of the two inequalities that form the compound inequality.
The same inequality can be written as so we know to shade the interval between 3 and 8, including those values. It would be read as "x is between 3 and 8, inclusive"
The graph of a compound inequality with the word or contains each graph of the two inequalities that form the compound inequality.
2­9 Compound Inequalities.notebook
October 18, 2016
Write an inequality for each word phrase:
1. all real numbers that are greater than ­2 and less than 6
2. all real numbers that are less than or equal to 0 or greater than 5
3. all real numbers that are greater than ­4 and less than 6
4. all real numbers that are less than 2.5 or greater than or equal to 5
Write a compound inequality that could represent each graph
2­9 Compound Inequalities.notebook
October 18, 2016
Solving Compound Inequalities: One way to solve a compound inequality is by separating it into two inequalities and solve each individually. Don't forget to flip inequalities if you multiply or divide by a negative number!! Another way of solving a compound inequality with the word and is by working on all 3 parts of the inequality. You perform the inverse operations to isolate the variable within the inequality symbols
2­9 Compound Inequalities.notebook
October 18, 2016
Or inequalities need to be solved separately. Find and graph the solutions to each compound inequality.
2­9 Compound Inequalities.notebook
October 18, 2016
To earn a B in your Algebra class, you must achieve an un­rounded test average between 84 and 86, inclusive. You scored an 86, 85, and 80 on the first three tests of the grading period. What possible scores can you earn on the fourth test to earn a B in the course?
The acidity of the water in a swimming pool is considered normal if the average of three pH readings is between 7.2 and 7.8, inclusive. The first two readings of the day for a swimming pool are 7.4 and 7.9. What possible values for the third reading p will make the average pH normal?