Mrs. Rivas International Studies Charter School.

1. Mrs. Rivas International Studies Charter School. Bell Ringer Evaluate if and . a) b) c) d)

2. Chapter 2 Section 1

3. The Addition Property of Equality 2.1 Identify linear equations. Use the addition property of equality. Simplify, then use the addition property of equality. 2 3

4. Remember that an equation (to solve) includes an equals symbol which distinguishes is from an expression (to simplify or evaluate). Equation Expression Definitions. An equation is a statement asserting that two algebraic expressions are equal. A solution of an equation is a number that makes the equation true when it replaces the variable. An equation is solved by finding it solution set, the set of all solutions. Equations with exactly the same solution sets are equivalent equations. Slide 2.1-3

5. Objective 1 Identify linear equations. Slide 2.1-4

6. Linear Equation in One Variable A linear equation in one variable can be written in the form where A, B, and C are real numbers, and with A≠ 0. Linear Equations Identify linear equations. The simplest type of equation is a linear equation. Nonlinear Equations Slide 2.1-5

7. Objective 2 Use the addition property of equality. Slide 2.1-6

8. Addition Property of Equality If A, B, and C are real numbers, then the equations andare equivalent equations. That is, we can add the same number to each side of an equation without changing the solution. Use the addition property of equality. To solve an equation, add the same number to each side. The justifies this step. Equations can be thought of in terms of a balance. Thus, adding the same quantity to each side does not affect the balance. Slide 2.1-7

9. The solution set is . The final line of the check does not give the solution to the problem, only a confirmation that the solution found is correct. Do NOT write the solution set as {x = 9}. This is incorrect notation. Simply write {9}. EXAMPLE 1 Applying the Addition Property of Equality Solve. Solution: Check: Slide 2.1-8

10. The solution set is . EXAMPLE 2 Applying the Addition Property of Equality Solve. Solution: Check: Slide 2.1-9

11. Use the addition property of equality. (cont’d) The addition property of equality says that the same number may be addedto each side of an equation. In Section 1.5, subtraction was defined as addition of the opposite. Thus, we can also use the following rule when solving an equation. The same number may be subtracted from each side of an equation without changing the solution. Slide 2.1-10

12. The solution set is . EXAMPLE 3 Applying the Addition Property of Equality Solve. Check: Solution: Slide 2.1-11

13. The solution set is . EXAMPLE 4 Subtracting a Variable Expression Solve. Solution: Check: Slide 2.1-12

14. The solution set is . EXAMPLE 5 Applying the Addition Property of Equality Twice Solve. Solution: Check: Slide 2.1-13

15. Objective 3 Simplify, and then use the addition property of equality. Slide 2.1-14

16. The solution set is . EXAMPLE 6 Combining Like Terms When Solving Solve. Solution: Check: Slide 2.1-15

17. The solution set is . Be careful to apply the distributive property correctly, or a sign error may result. EXAMPLE 7 Using the Distributive Property When Solving Solve. Solution: Check: Slide 2.1-16