1. Lesson 2.4 Variables and Equations

2. Types of equations An equation is a mathematical sentence with an equal sign.

3. Classifying Equations An equation with one or more variables is an open sentence. An equation with a numerical expression equal to another numerical expression is either true or false.

4. Writing Equations

5. Solutions to Equations A solution is a value for a variable that makes an equation true. You substitute a number for a variable to determine whether the number is a solution of the equation.

6. CU 1 CU 1 State whether each equation is true, false, or an open sentence. Explain. a. a.3(b - 8) = 12 b. 7 - (-6) = 1 c. -9 + 5 = -4

7. CU 2 CU 2 Write an equation. State whether the equation is true, false, or an open sentence. Explain. Six times a number added to the number is the opposite of forty-two.

8. CU 3 Is 45 a solution of the given equation? 120 + x = 75

9. CU 4 A gift pack must hold 20 lb of food. Apples weigh 9 lb and cheese weighs 5 lb. Can the jar of jam that completes the package weigh 7 lb?

10. Tonight’s Assignment Re-teach 2.2 and 2.3