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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?