Absolute Value
Absolute Value
Rules and Properties Absolute-Value Equations If  a  > 0 and | x | =  a , then  x  =  a  or  x  = – a . 1.8 Solving Absolute-Value Equations and Inequalities Absolute-Value Inequalities If  a  > 0 and | x | <  a , then  x  > – a  and  x  <  a . If  a  > 0 and | x | >  a , then  x  < – a  or  x  >  a . Similar statements are true for | x |     a  and | x |     a.
Absolute Value Rules If you start with an “=“ sign then you will have an “or” statement. If you start with a “<“ or a “ ≤” then you will have an “and” statement. If you start with a “>” or a “≥” then you will have an “or” statement.
Example 1 Solve and graph absolute-value equations. | x  + 1| = 7 1.8 Solving Absolute-Value Equations and Inequalities
Example 1 Solve and graph absolute-value equations. | x  + 1| = 7 1.8 Solving Absolute-Value Equations and Inequalities x  + 1 = 7 or x  + 1 = –7 x  = 6 or x  = –8
Example 2 Solve and graph absolute-value equations. 4| x | = 8 1.8 Solving Absolute-Value Equations and Inequalities
Example 2 Solve and graph absolute-value equations. 4| x | = 8 1.8 Solving Absolute-Value Equations and Inequalities 4 x  = 8 or 4 x  = –8 x  = 2 or x  = –2
Example 3 |x - 4| = x + 1
Example 3 |x - 4| = x + 1   x = x + 5   or   x – 4 = -x - 1 0 = 5   or   2x – 4 = -1 x - 4 = x + 1 x - 4 = -(x + 1) No Solution or   2x = 3 No Solution or   x = 3/2  3/2
Example 4 Solve and graph absolute-value inequalities. | x  + 52|   76  1.8 Solving Absolute-Value Equations and Inequalities
Example 4 Solve and graph absolute-value inequalities. | x  + 52|   76  x +  52   76 or x  + 52     - 76 x    24 or x    – 128 1.8 Solving Absolute-Value Equations and Inequalities
Example 5 Solve and graph absolute-value inequalities. | x  + 52|   76  1.8 Solving Absolute-Value Equations and Inequalities
Example 5 Solve and graph absolute-value inequalities. | x  + 52|   76  x +  52   76 and x  + 52     -76 x    24 and  x    –128 1.8 Solving Absolute-Value Equations and Inequalities

Pres Absolute Value Inequalities (Section 1.8)

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    Rules and PropertiesAbsolute-Value Equations If a > 0 and | x | = a , then x = a or x = – a . 1.8 Solving Absolute-Value Equations and Inequalities Absolute-Value Inequalities If a > 0 and | x | < a , then x > – a and x < a . If a > 0 and | x | > a , then x < – a or x > a . Similar statements are true for | x |  a and | x |  a.
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    Absolute Value RulesIf you start with an “=“ sign then you will have an “or” statement. If you start with a “<“ or a “ ≤” then you will have an “and” statement. If you start with a “>” or a “≥” then you will have an “or” statement.
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    Example 1 Solveand graph absolute-value equations. | x + 1| = 7 1.8 Solving Absolute-Value Equations and Inequalities
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    Example 1 Solveand graph absolute-value equations. | x + 1| = 7 1.8 Solving Absolute-Value Equations and Inequalities x + 1 = 7 or x + 1 = –7 x = 6 or x = –8
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    Example 2 Solveand graph absolute-value equations. 4| x | = 8 1.8 Solving Absolute-Value Equations and Inequalities
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    Example 2 Solveand graph absolute-value equations. 4| x | = 8 1.8 Solving Absolute-Value Equations and Inequalities 4 x = 8 or 4 x = –8 x = 2 or x = –2
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    Example 3 |x- 4| = x + 1
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    Example 3 |x- 4| = x + 1 x = x + 5 or x – 4 = -x - 1 0 = 5 or 2x – 4 = -1 x - 4 = x + 1 x - 4 = -(x + 1) No Solution or 2x = 3 No Solution or x = 3/2 3/2
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    Example 4 Solveand graph absolute-value inequalities. | x + 52|  76 1.8 Solving Absolute-Value Equations and Inequalities
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    Example 4 Solveand graph absolute-value inequalities. | x + 52|  76 x + 52  76 or x + 52  - 76 x  24 or x  – 128 1.8 Solving Absolute-Value Equations and Inequalities
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    Example 5 Solveand graph absolute-value inequalities. | x + 52|  76 1.8 Solving Absolute-Value Equations and Inequalities
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    Example 5 Solveand graph absolute-value inequalities. | x + 52|  76 x + 52  76 and x + 52  -76 x  24 and x  –128 1.8 Solving Absolute-Value Equations and Inequalities