17
How do I solve absolute value equations and inequalities?

How do I solve absolute value equations and inequalities?

Embed Size (px)

Citation preview

• How do I solve absolute value equations and inequalities?

2.2 Solve Absolute Value Equations and Inequalities

Example 1 Solve a simple absolute value equationSolve a simple absolute value equation

Solve . Graph the solution.63 xWrite original equation.63 xWrite equivalent equations.

___3 x ___3or x6 6

Solve for x._____x _____or x63 63Simplify.___x ___or x3 9

The solutions are ____ and ___. These are the values of x that are ___ units away from ___ on a number line.

3 96 3

l l l l l l l l l l l l l l l l l

6 units 6 units

2.2 Solve Absolute Value Equations and Inequalities

Checkpoint. Solve the equation. Then graph the solution Checkpoint. Solve the equation. Then graph the solution

5 1. x5x 5or x

l l l l l l l l l l l l l l l l l

5 units 5 units

25 2. x25 x 25or x

3x 7or x

l l l l l l l l l l l

2 units 2 units

2.2 Solve Absolute Value Equations and Inequalities

Example 2 Check for extraneous solutionsCheck for extraneous solutions

Solve . Check for extraneous solutions.xx 6104 Write original equation.

xx 6104 ___104 x ___104or xx6 x6 Expressions can

equal ____ or _____.x6 x6Subtract _____ from each side.

x4_____10 _____01or x2 x10

Solve for x.x___ x___or 5 1Check the apparent solutions to see if either is extraneous.

2.2 Solve Absolute Value Equations and Inequalities

Example 2 Check for extraneous solutionsCheck for extraneous solutions

Solve . Check for extraneous solutions.xx 6104 Check

xx 6104

__610__4?

xx 6104

__610__4?

5 5 1 1

______?

______?

30 30 6 6

______ 30 30 ______ 6 6The solution is ___. Reject ____ because it is an ___________ solution.

5 1 extraneous

2.2 Solve Absolute Value Equations and Inequalities

Checkpoint. Solve the equation. Check for extraneous Checkpoint. Solve the equation. Check for extraneous solutions. solutions.

1152 3. x1152 x 1152 x

5 56x2

2 2x 3

5 516x2

2 2x 8

11532?

11582?

1111 1111

2.2 Solve Absolute Value Equations and Inequalities

Checkpoint. Solve the equation. Check for extraneous Checkpoint. Solve the equation. Check for extraneous solutions. solutions.

xx 6183 4. xx 6183 xx 6183

x3 x3x318

3 3x 6

x3 x3x918

9 9x 2

661863?

261823?

3636 1212

2.2 Solve Absolute Value Equations and Inequalities

Rewrite the absolute value equation as two linear equations. Rewrite the absolute value equation as two linear equations.

23 1. x

Pg. 31 #1 and 17Pg. 31 #1 and 17

23 x 23or xSolve the equation. Solve the equation.

84 17. x84 x 84or x

4 4x 4

4 4x 12

2.2 Solve Absolute Value Equations and Inequalities

Example 3 Solve an inequality of the form .Solve an inequality of the form .cbax

The absolute value inequality is equivalent to.___52or ____52 xx 3

Solve . Then graph the solution.352 x

First Inequality Second InequalityWrite inequalities.___52 x ___52 x

3

3 3Subtract __ from each side.

5___2 x ___2 x8 2Divide each side by ___.2

___x ___x4 1

The solution are all real numbers less than ____ or greater than ____.

41

l l l l l l l l l l l l l l l l l

2.2 Solve Absolute Value Equations and Inequalities

Example 4 Solve an inequality of the form .Solve an inequality of the form .cbax Solve . Then graph the solution.5.45.1 x

Write inequality.5.45.1 x

The solution is between ____ and ____, inclusive.3 6

l l l l l l l l l l l l l l l l l

___5.1____ x5.4 5.4 Write equivalent compound inequality.

Add ____ to each expression.

5.1_______ x3 6

2.2 Solve Absolute Value Equations and Inequalities

Checkpoint. Solve the inequality. Then graph the solution. Checkpoint. Solve the inequality. Then graph the solution.

72 5. x

72 x 72or x2 2x 9

2 2x 5

l l l l l l l l l l l l l l l l l

2.2 Solve Absolute Value Equations and Inequalities

Checkpoint. Solve the inequality. Then graph the solution. Checkpoint. Solve the inequality. Then graph the solution.

914 6. x

9149 x1 1

1084 4

2

1 x4

4x 5.2

l l l l l l l l l

2.2 Solve Absolute Value Equations and Inequalities

Rewrite the absolute value inequality as a compound inequality. Rewrite the absolute value inequality as a compound inequality.

74 21. x

Pg. 32 #21, 24, 36, and 37Pg. 32 #21, 24, 36, and 37

7 4x 765 24. x65 x or 65 x

2.2 Solve Absolute Value Equations and Inequalities

Pg. 32 #21, 24, 36, and 37Pg. 32 #21, 24, 36, and 37Solve the inequality. Solve the inequality.

31 36. x31x 31or x

1 1x 2

1 1x 4

2or 4 xx

2.2 Solve Absolute Value Equations and Inequalities

Pg. 32 #21, 24, 36, and 37Pg. 32 #21, 24, 36, and 37Solve the inequality. Solve the inequality.

932 37. x 9 32 x

336

3x2 12

9

2 2 2

3 x 6

2.2 Solve Absolute Value Equations and Inequalities

Pg. 31, 2.2 #1-43

Textbook pg 30 #1-15, 16-28