# Can we go on! You have 5 minutes to complete check-up.

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Can we go on! You have 5 minutes to complete check-up.

Lets Check! 1.8 to 5 2.4 to 19 3.6 to 23 4.16 to 10 and 24 to 15 5.75meter/30sec. 2.5m/sec 6.\$8.75 per scarf 7.Danny 8.12 men

Writing and Solving Proportions I can write and solve proportions using ratios and algebra. Textbook Pages 418-428

Vocabulary Proportion: is an equation that states that two ratios are equivalent. 3/5 = 6/10 This is read “3 is to 5 as 6 is to 10” Algebra form: a/b = c/d where b and d are nonzero numbers

Using Equivalent Ratios: When one of the numbers in a proportion is unknown, you can find the number by solving the proportion.

Use equivalent ratios A person burns about 210 calories in 30 minutes of skating. About how many calories would the person burn in 60 minutes. First write yourself a proportion. 210 calories/30 minutes = C/60 minutes Ask yourself what can I multiply 30 by to get to 60. 2 Because you multiplied the 30 by 2 to get 60, you must multiply the 210 by 2. Which gives you? 420

Try some 1/5 = z/20 4 8/3 = k/18 48 9/c=3/12 36

Solve proportions using algebra The same method you used to solve division equations can be used to solve proportions with the variable in the numerator. 6 = x 10 25 Since this is x divide by 25, you must do the opposite. So multiply both sides by 25. So that will give you 150/10 = x 15=x

Try some 4/14 = m/49 Multiply both sides by 49 14 = m 25/30 = x/12 Multiply both side by 12 10= x h/33 = 2/6 Multiply both side by 33 h = 11

Cross Products Cross Product: when you multiply the numerator of each ratio by the denominator of the other ratio. The cross products of proportions are equal to each other. So use cross products form an equation. 4 = 10 6 x 6 * 10 = 4*x 60 = 4x solve by dividing both sides by 4 15=x

Try some! k/27 = 4/6 6k=108 divide both sides by 6 K=18 20/16= n/12 16n = 240 divide both sides by 16 n=15

Use cross product to tell if equal 24/104, 3/13 Yes 6/7, 21/18 No 3.4/4.3, 5.6/6.5 No

Practice Workbook Pages 105-108 evens

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