1 8 An Introduction to Equations Vocabulary Equation

1 -8 An Introduction to Equations

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.

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.

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.

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.

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? ”

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.

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