A1-U1.7 Lesson: Absolute Value Equations

Open Ended

ACT Prep Warm-Up:

Error Analysis: Jess solves the following: $$13<5n-2\ or\ 3n+1>4n\ +4$$

Here are her steps:

1) Add two to both sides of the first inequality, then divide both sides by five.

2) Subtract 3n and 4 from both sides, then divide by negative one.

3) Graph: Open at n>3, and open at n<-3, shading toward the infinities.

Is she correct? If not explain what should have been done.

Unit 1 Lesson 7a Absolute Value Equations

Distance from zero. Always expressed as a whole number.

Absolute Value

Concepts:

Multiple Choice

Evaluate: $$\left|7\right|$$

• 7

• -7

• 0

• 49

Multiple Choice

Evaluate: $$\left|-12\right|$$

• 12

• -12

• 144

• 0

​Procedure:

1) Isolate the absolute value.
2) Drop the absolute value bars.
3) Write two equations with opposite outputs.
4) Use inverse operations to solve.
5) Express your answers.

Reorder

Reorder the following steps used to solve absolute value equations.

• Isolate the absolute value.

• Drop the absolute value bars.

• Write two equations with opposite outputs.

• Use inverse operations to solve.

• Express your answers.

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Example 1:

Example 2:

Multiple Choice

Solve: $$\left|-5-2x\right|-9=4$$

• -9, 4

• 9, -4

• -9, -4

• 9, 4