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2.5 Solving Proportions

Write and use ratios, rates, and unit rates.Write and solve proportions.

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• A ratio is a comparison of two quantities.• A ratio can be written as

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Example: Reduce Ratios

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Practice

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• A rate is a ratio of two quantities with different units.

• A unit rate is a rate with a second quantity of 1 unit.

• You can convert any rate into a unit rate.

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Example: Divide Rates

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Practice

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• A statement that two ratios are equal is called a proportion.

• You can solve a proportion by using the cross products property, then an inverse operation.

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Example: Cross Multiply, Divide

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Practice

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• A percent is a ratio that compares a number to 100.

• You can use the following proportion to find unknown values.

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Examples

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Practice

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• Proportions are used to create scale drawings and scale models.

• A scale is a ratio between two sets of measurements.

• A scale drawing or scale model uses a scale to represent an object as smaller or larger than the actual object.

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Example

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REVIEW

1) What is a ratio?

2) What is a rate?

3) What is a proportion?

4) What is a scale drawing?