1 / 12

Proportions

Proportions. Proportion – two equal ratios. 1 = 4 3 = 15 2 8 5 25 7 = 21 a = c 8 24 b d. Do the ratios form a proportion? 3 9 In a proportion, the 7 21 cross products are

annaswan
Download Presentation

Proportions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Proportions

  2. Proportion – two equal ratios 1 = 43 = 15 2 8 5 25 7 = 21a = c 8 24 b d

  3. Do the ratios form a proportion? 39 In a proportion, the 7 21 cross products are equal. 3 • 21 = 63 Yes, the ratios 7 • 9 = 63 form a proportion.

  4. Do the ratios form a proportion? 28 Yes 10 40 912 No 12 15

  5. Solving Proportions: You can solve for a missing value in a proportion. 1) cross multiply to form an equation 2) solve the equation to find the missing value

  6. Examples: x = 9 12x = 36 4 12 x = 3 y = 18 45y = 90 5 45 y = 2

  7. Solve these proportions: 8 = 20 n 30 20n = 240 n = 12

  8. 5 = 35 8 x 5x = 280 x = 56

  9. You can use a proportion to solve an everyday problem. If you can buy three posters for $9.60, how many can you buy for $48.00?

  10. 3 posters = x posters $ 9.60 $48.00 $ 9.60x = $ 144.00 x = 15

  11. At the Copy Shop, 18 copies cost $1.08. How much will 40 copies cost? 18 copies = 40 copies $1.08 $ y 18y = $43.20 y = $ 2.40

  12. If you can drive 100 miles in 4 hours, how many miles can you drive in 10 hours? 100 miles = x miles 4 hours 10 hours 4x = 1000 x = 250 miles

More Related