Pearson Algebra 1 Common Core, 2011
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Pearson Algebra 1 Common Core, 2011 View details
6. Compound Inequalities
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Exercise 16 Page 204

Split the compound inequality into two separate ones and solve them individually.

Solution: - 21≤ q≤ 33
Graph:

Practice makes perfect

We are given the following compound inequality. - 3≤ 6-q/9≤ 3 Sometimes, it can be helpful to write a compound inequality as two individual inequalities. This lets us solve each one separately. - 3≤6-q/9 and 6-q/9≤ 3Now we can solve them separately and later compare their solution sets.

First Inequality

Inequalities can be solved in the same way as equations, by performing inverse operations on both sides until the variable is isolated. The only difference is that when you divide or multiply by a negative number, you must flip the inequality sign.

- 3≤6-q/9
- 27≤ 6-q
- 33≤- q
33≥ q
q≤ 33

The first inequality is satisfied by all values less than or equal to 33.

Second Inequality

Once more, we will solve the inequality by isolating the variable.

6-q/9≤ 3
â–¼
Solve for q
6-q≤ 27
- q≤ 21
q≥ - 21

The second inequality is true for all values greater than or equal to - 21.

Combining Solution Sets

Finally, we can combine the obtained solution sets. The first inequality, q≤ 33, describes all values less than or equal to 33. We can represent this by using a closed circle at 33 and shading the values to the left.

The second inequality, q≥ - 21, describes all values greater than - 21, including - 21. For this, we will use a closed circle again, this time at - 21 and shade the values to the right.

The intersection of these solution sets, - 21≤ q≤ 33, describes the solutions of the compound inequality.