Bellringer 82 cookies 30 cupcakes 9 hotdogs 1
Bellringer 82 cookies / 30 cupcakes 9 hotdogs / 1 hour 1. Which is a rate? 2. Which is a unit rate? 3. Find the unit rate for 55 cakes / 5 miles.
Go over Homework Reteach 5 -2 Reteach 5 -3
Ch. 5 -3 & 5 -4 Proportions & Solving Proportions
: a Ak ss o r c tiply l u M cross products two products found by multiplying the denominator of each ratio by the numerator of the other ratio 20 = 6 90 = 90 6=9
proportion an equation stating that two ratios are equal – use cross products to determine if a proportion or not No, not a proportion 20 = 6 90 = 90 Yes a proportion 6=9 No, not a proportion
Example 1: Determine whether the following ratios form a proportion. a. ) Yes, because cross products are equal 60 = 60 b. ) No, because cross products are not equal 10 = 8
Example 2: Solve each proportion below by using the cross products. a. ) b. ) Times the couple together 9 & 10 Times the couple together 4 & 21 Then divide by the lonely guy 2 Then divide by the lonely guy 12 X = 45 c. ) x=7 d. ) Times the couple together 12 & 6 Times the couple together 20 & 9 Then divide by the lonely guy 8 Then divide by the lonely guy 15 x=9 x = 12
Example 3: Set up a proportion for each scenario below and solve by doing the cross products. a. ) Andy paid $1. 29 for 3 pieces of candy. At that rate, what would 8 pieces of candy cost? Times the couple together 1. 29 & 8 Then divide by the lonely guy 3 x = $3. 44 b. ) You are visiting friends in Estonia. Suppose the exchange rate is 12. 68 kroons = 1 dollar. How many Estonia kroons will you receive if you have $500? Times the couple together 12. 68 & 500 Then divide by the lonely guy 1 x = 6, 340 kroons
8 20 12 4 10 8 Which triangles are similar? If they are in proportion they are similar.
8 20 12 4 10 8 20 x 4 ? ? 8 x 10 8 x 8 ? ? 12 x 4 Equal => Yes Equal => NO 12 x 10 ? ? 20 x 8 Equal => NO Blue and Red are similar (they are in proportion)
Homework PS 5 -4 all
Homework Pg. 240 #10 -26 even (1 pt each) Pg. 247 #12 -24 even (1 pt each)
Bellringer 8 20 12 4 10 8 Which triangles are similar? If they are in proportion they are similar.
Go over Homework Pg. 240 #10 -26 even Pg. 247 #12 -24 even
Proportion Project Head and Shoulders Practice Sheets 5 -3 & 5 -4 • Do in class • If not completed homework
- Slides: 15