Solving Inequalities by Adding and Subtracting

By Jonathan Chen, Paul Lee, Justin Ellis

Prior Knowledge

Inequalities

Addition/Subtraction

Variables

Inequality signs

Vocabulary

1.Inequality: A statement formed by placing an inequality symbol between two expressions

2. < :Lesser than3. > :Greater than4. ≤ : Less than or equal to5. ≥ : Greater than or equal to6. Addition Property of Inequality: This means that if a<b, then a+c<b+c.7. Subtraction Property of Inequality: This means that if a<b, then a-c <b-c.

Main Idea

The main idea of this section is to simplify the inequality so we can work with it

Steps

The first step is to isolate the variable

Step 1: Isolating the Variable

x+2<7 -2-2

Why is this???

x+2<7

Step 2: Simplify

-2 -2x<7-2

7-2=5

x<5

Example Problem

Solve X+5>3.

X+5>3 Write down the inequality X+5-5>3-5 Subtract 5 from each side

X>-2 Simplify

The End

References:•Algebra Textbook- Chapter 6 section 1, pg 323•Class Notes- Unit 3, Concept: Solving Inequalities by Adding or SubtractingOctober 3, 2012