Download Lesson 1.7

Lesson 1.7
Solve Absolute Value Equations and
Inequalities
Objective
• Solve absolute value equations and
inequalities
Standard 1.0
• Students will solve equations and inequalities
involving absolute value
Absolute value
• A number x written x , is the distance the
number is from 0 on the number line
• Question
– What numbers are 1 unit from 0 on the number
line?
– What numbers are 1 unit from 5 on the number
line?
Solving Absolute value equations
• Examples
1.
x 5  7
2.
5x 10  45
ax  b  c
Where c>0
Step 1: Write two equations: ax + b = -c or ax + b = c
Step 2: Solve each equation
Step 3: Check each solution in the original equation
Indy Practice
1.
2 x  12  4 x
2.
4x 1  2x  9
Compound Absolute Value Inequalities
How do you remember And/OR?
• Greater than
–m
ORe than
• Less than
–Less th
AND
Example
4 x  5  13
Indy Practice
2x  7  1
Welcome to the Real World
• A professional baseball should weigh 5.125
ounces, with a tolerance of 0.125 ounce.
Write and solve an absolute value inequality
that describes the acceptable weights for the
ball
Actual Weight - Ideal Weight
≤ Tolerance
Homework
p.55 #3, 7, 20, 30, 38, 56, 81