mgb5e_ppt_7_6

# mgb5e_ppt_7_6 - Â 7.6 Proportions and Problem Solving with...

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Unformatted text preview: Â§ 7.6 Proportions and Problem Solving with Rational Equations Martin-Gay, Beginning Algebra, 5ed 2 Ratios and Rates Ratio is the quotient of two numbers or two quantities. The units associated with the ratio are important. The units should match. If the units do not match, it is called a rate , rather than a ratio. The ratio of the numbers a and b can also be written as a : b , or . b a Martin-Gay, Beginning Algebra, 5ed 3 Proportion is two ratios (or rates) that are equal to each other. d c b a = We can rewrite the proportion by multiplying by the LCD, bd. This simplifies the proportion to ad = bc. This is commonly referred to as the cross product . Proportions Martin-Gay, Beginning Algebra, 5ed 4 Solve the proportion for x . 3 5 2 1 = + + x x ( 29 ( 29 2 5 1 3 + = + x x 10 5 3 3 + = + x x 7 2 =- x 2 7- = x Solving Proportions Continued. Example: Martin-Gay, Beginning Algebra, 5ed 5 3 5 2 3 2 5 =-- true Substitute the value for x into the original equation, to check the solution. So the solution is 2 7- = x 7 2 7 1 5 3 2 2 + = +-- Solving Proportions Example continued: Martin-Gay, Beginning Algebra, 5ed 6 If a 170-pound person weighs approximately 65 pounds on Mars, how much does a 9000-pound satellite weigh? Mars on satellite pound- x Mars on person pound- 65 Earth on satellite pound- 9000 Earth on person pound- 170 = 000 , 585 65 9000 170 = â‹… = x pounds 3441 170 / 585000 â‰ˆ = x Solving Proportions Example: Martin-Gay, Beginning Algebra, 5ed 7 Given the following prices charged for various sizes of picante sauce, find the best buy....
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## This note was uploaded on 06/10/2009 for the course MAC 1103 taught by Professor Prescott during the Spring '09 term at Pasco-Hernando Community College.

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mgb5e_ppt_7_6 - Â 7.6 Proportions and Problem Solving with...

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