1. 1-8 An Introduction to Equations

2. Vocabulary Equation: A mathematical sentence that uses an equal sign. Open Sentence: An equation is an open sentence if it contains one or more variables and it may be true or false depending on the value of the variables. Solution of an equation: Any value or values that make an equation true.

3. Problem #1 Classifying Equations Is the equation true, false, or open? Explain. If an equation contains only numbers, simplify each side to determine if the expressions are equal. If there is a variable in the equation, it is open.

4. Problem #2 Identifying Solutions of Equations To determine whether a number is a solution to the equation, substitute the number for the variable in the equation. Simplify each side to determine whether the equation is true.

5. Problem #3 Writing an Equation In real-world problems, the word is can indicate equality. You can represent some real-world problems using an equation.

6. Problem #4 Using Mental Math to Find Solutions Use mental math to find the solution to the equation. Ask yourself, “what number subtracted from 12 is 3?”

7. Problem #5 Using a Table to Find a Solution Use a table to find the solution to the equation. Use mental math to substitute values like 0, 1, or 10. Use these values to find a good starting point for your table.

8. Problem #6 Estimating a Solution To estimate a solution, find the integer values of x between which the solution must lie. Use a table.