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Lesson 38
Course 3 (student notes)
Objective: TSW solve equations using the properties of equality.
Inverse operations undo each other.
Addition and Subtraction are inverse operations
Multiplication and Division are inverse operations
We use inverse operations to isolate the variable in an equation.
Performing the same operation on both sides of an equation preserves the equality of the equation. Below
are four properties of equality we can use to manipulate equations.
Example 1.
After spending $2.30, Robert had $5.70. How much money did he have before he spent $2.30? Solve this
equation to find the answer.
Example 2.
If a 12-month subscription to a magazine costs $8.40, what is the average cost per month? Solve this equation
to find the answer.
Question: In the context of this problem, what does m= 0.70 mean?
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Example 3.
YOU TRY!!!
Example 4