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Federal Way Public Schools  
Number Sense
Lesson 6
Ratio and Proportion
  Objectives/Vocab/Tips > Examples 1 | 2 | 3 > Practice: 1 | 2 | 3 > Reflection

Example 1:

Solve for x in the following proportion.

5 / 9 = x / 81

Here is one way to find the solution to this problem:

Step 1: We begin by setting up our problem using cross multiplication.

5 * 81 = x * 9

Step 2: Next, we need to find the missing value, x, by getting it by itself on one side of the equation.

405 = 9x
405/9 = 9x / 9
45 = x

 

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