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Table of Contents. Topic Page #. . 3.4B Many or No Solution 33. 3.8A Solving Equations 35. 3.8B Solving Formulas 37. 6.5 Absolute Value Equations 39. 3.5/3.6 Ratios and Proportions 41. 3.5/3.6 Ratios and Proportions. #41. Ratio:.
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Table of Contents Topic Page # ... 3.4B Many or No Solution 33 3.8A Solving Equations 35 3.8B Solving Formulas 37 6.5 Absolute Value Equations 39 3.5/3.6 Ratios and Proportions 41
Ratio: Relation between 2 numbers a b a:b a to b
You always have to write ratios in the simplest form. You never write the answer as a mixed fraction
Ex 1: Cell phone A person makes 6 long distance calls and 15 local calls in 1 month. a. Find the ratio of long distance calls to local calls. 6 15 2 5 =
Ex 1: Cell phone A person makes 6 long distance calls and 15 local calls in 1 month. b. Find the ratio of local calls to long distance calls 15 6 5 2 =
Ex 1: Cell phone A person makes 6 long distance calls and 15 local calls in 1 month. c. Find the ratio of long distance calls to all calls. 6 21 2 7 =
Ex 2: Sports A volleyball team plays 14 home matches and 10 away matches. a. Find the ratio of home matches to away matches. 14 10 7 5 =
Ex 2: Sports A volleyball team plays 14 home matches and 10 away matches. b. Find the ratio of home matches to all matches. 14 24 7 12 =
Ex 2: Sports A volleyball team plays 14 home matches and 10 away matches. c. Find the ratio of away matches to all matches. 10 24 5 12 =
Proportions: When two ratios are equal (bd) (bd) ad = bc
Cross multiply ad = bc
Ex #3: Solve. 6k = 90 6 6 k = 15
Ex #3: Solve. 4x = 36 4 4 x = 9
Reduce around the box 3 1 4x = 36 4 4 x = 9 x = 9
1 3 8t = 120 t = 15 t = 15
y = 9 y = 9
1 2 3(x + 8) = 6x 2x = x + 8 3x + 24 = 6x x = 8 24 = 3x 8 = x
3 1 24(x – 12) = 8x 3x – 36 = x 24x – 288 = 8x 2x – 36 = 0 –288 = –16x 2x = 36 18 = x x = 18
Ex #4: Architect An architect creates a scale model of a school. The school is 50 feet high. The ratio of the model to the actual school is 1 foot to 75 feet. Estimate the height of the model.
2 3 3h = 2 h =
Ex #5: A map has a scale factor of 1cm : 15km. If the distance of the map is 6cm, find the actual distance. x =
Ex #6: Write the sentence as a proportion and solve. 1 4 x =
Ex #6: Write the sentence as a proportion and solve. 2 1 4 1 x =