PROPORTIONS 6-2. VOCABULARY Proportion – equality of two ratios Cross Products – the results...

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PROPORTIONS 6-2

Transcript of PROPORTIONS 6-2. VOCABULARY Proportion – equality of two ratios Cross Products – the results...

Page 1: PROPORTIONS 6-2. VOCABULARY Proportion – equality of two ratios Cross Products – the results when you cross multiply.

PROPORTIONS

6-2

Page 2: PROPORTIONS 6-2. VOCABULARY Proportion – equality of two ratios Cross Products – the results when you cross multiply.

VOCABULARY

Proportion – equality of two ratiosCross Products – the results when you cross multiply

Page 3: PROPORTIONS 6-2. VOCABULARY Proportion – equality of two ratios Cross Products – the results when you cross multiply.

KEY CONCEPTS

In a proportion, the ratios and the cross products are equal to each other.Example:

6 = 8 `

9 12 72 = 72

Page 4: PROPORTIONS 6-2. VOCABULARY Proportion – equality of two ratios Cross Products – the results when you cross multiply.

Examples…

Tell whether the two ratios form a proportion.

1. 6 = 4 2. 15 = 5 9 6 20 7

36 = 36

yes

105 = 100

no

Page 5: PROPORTIONS 6-2. VOCABULARY Proportion – equality of two ratios Cross Products – the results when you cross multiply.

To solve a proportion that contains a variable, cross multiply.

Example: x = 4 `

9 66x = 36

Now you must get the x by itself, so reverse the operation.6x = 36

6 6

x = 6

Page 6: PROPORTIONS 6-2. VOCABULARY Proportion – equality of two ratios Cross Products – the results when you cross multiply.

REAL WORLD PROBLEM100 nautical miles equals about 115 standard miles. To the nearest mile, how far in standard miles is 156 nautical miles?

Nautical milesStandard miles

100 = 156 115 m100m = 17,940

100m = 17,940 100 100

m = 179.4 156 nautical miles is about 179 standard miles