1. Organize Binders -Move ch. 3 notes to “old notes” -Move review sheet to “review” -Move Quiz to “quiz” -Throw away old homework

2. 4-1 Ratios and Proportions Objective: To determine if two ratios are equal and to solve proportions. NEW STAMP LOG!

3. Vocabulary Ratio: A comparison of 2 numbers using division ▫Examples: Proportion: An equation stating that two ratios are equal ▫Examples:

4. Examples 1.Write the ratio of “x to y”. 2.If there are 12 cats and 4 dogs, write the ratio of: 1.Cats to Dogs 2.Dogs to Cats Sidenote: You can (and should) reduce a ratio!!!

5. Comparing Ratios To tell if two ratios are equivalent (create a proportion), find the cross product. 628822 168 176 ≠ Answer: Not a proportion

6. TOO: Is it a proportion? 1)2) Answers: 1)Yes 2)No

7. Proportion: We already know that the fractions are equal Solve the Proportion CROSS MULTIPLY No more fractions! (8)(3) = (4)(x)

8. TOO: Solve the proportion 1)2) Answers: 1)a = 9 2)y = -63/16

9. Example Cross Multiply Distribute Solve 5(x + 2) = (3)(6)

10. Try with me 1) 2) 3) Answers: 1) w = 5 2) x = -10 3) x = 9

11. TOO: Watch your Negatives!!! 1) 2) 3) Answers: 1) r = 3/5 2) y = -13/4 3) x = -7/4

12. Homework Pg. 199 # 14 - 34