9_3 Equations and Absolute Value TROUT 09.ppt

persamaan nilai mutlak

1. 9.3 Equations and Absolute Value
Goal(s): To solve equations involving
absolute value

2. Solve: |x - 3| = 2
•What values can be substituted for “x” to
make the equation true?
5 or x 1

3. Solving Equations with Absolute Values
To solve an equation of the form
|A| = b
Solve the disjunction
A = b or A = -b
Solve for “x”: |x + 3| = 7
x + 3 = 7 x + 3 = -7
Do not write the absolute value brackets
when you set up the two different
equations.

4. Solve |2x – 4| = 10
x = 7
2 4 10x 
2 14x
2 4 10x 
2 6x
4 4
3xor

5. Solve |2x + 5| = 13
x = 4 or x = -9

6. Solve |3x + 7| = 19
26
4 or
3
x x

 

7. Solve |5x – 3| = -17
No solution. The
solution set is 

8. Solving |absolute value| equations:
The absolute value expression must
be “by itself” before writing the two
different equations.
113 7 |2x+5|
7 7
3|2 5| 18x 
3 3
|2 5| 6x 

9. Solve: |2x – 7| + 5 = 12
|2 7| 7x 
2 7 7x 
2 14x
7x
2 7 7x 
2 0x
0xor

10. Solve |2x + 5| -9 = 12
x = 8 or x = -13
+9 +9
|2x + 5| = 21

11. Solve: 3|2x + 5| -9 = 12
x = 1 or x = -6
+9 +9
3|2x + 5| = 21
3 3
2x + 5 = 7 2x + 5 = -7

12. Assignment:
Page 412
(12-32) even