Lesson 2.4Lesson 2.4Variables and EquationsVariables and Equations

Types of equationsTypes of equations• An equation is a mathematical

sentence with an equal sign.

Classifying EquationsClassifying 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.

Writing EquationsWriting Equations

Solutions to EquationsSolutions 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.

CU 1CU 1State whether each equation is true, false, or an open sentence. Explain.

a. 3(b - 8) = 12

b. 7 - (-6) = 1

c. -9 + 5 = -4

CU 2CU 2Write 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.

CU 3CU 3

Is 45 a solution of the given equation?

120 + x = 75

CU 4CU 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?

Tonight’s AssignmentTonight’s Assignment

Re-teachRe-teach

2.2 and 2.32.2 and 2.3