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4 5 12 16 20 2 find the numerator of the 3 the

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Unformatted text preview: respectively, or 1.5 and 2, or 45 and 60, or an infinite number of other combinations. All we know is that the ratio of numerator to denominator will be 3 : 4. Therefore, the numerator may be represented by 3x and the denominator by 4x. The fraction is then repre3x sented by . 4x 3 Example: The value of a fraction is . If one is subtracted from the numerator and added to the denominator, 31 the value of the fraction is . Find the original fraction. 2 2 Solution: Represent the original fraction as 3x . If one is subtracted from the numerator and added to the denominator, the new fraction is 2 x − 1 . The value of this new fraction is 1 . 2x − 1 1 = 3x + 1 2 3x + 1 2 2x Cross multiply to eliminate fractions. 4 x − 2 = 3x + 1 x=3 The original fraction is 2x 6 , which is . 3x 9 www.petersons.com Problem Solving in Algebra 179 Exercise 5 Work out each problem. Circle the letter that appears before your answer. 1. A fraction is equivalent to 4 . If the numerator 5 4. is increased by 4 and the denominator is increased by 10, the value of the resulting fraction is (A) (B) (C) (D) (E) 2. 4 5 12 16 20 2 . Find the numerator of the 3 The denominator of a certain fraction is 5 more than the numerator. If 3 is added to both numerator and denominator, the value of the new fraction is 2 . Find the original fraction. (A) (B) (C) (D) (E) 3 8 4 9 11 16 12 17 7 12 3 original fraction. What number must be added to both the numerator and the denominator of the fraction 5 3 to give a fraction equal to ? 21 7 5. The denominator of a fraction is twice as large as the numerator. If 4 is added to both the numerator and denominator, the value of the fraction is (A) (B) (C) (D) (E) 6 10 12 14 16 5 . Find the denominator of the 8 (A) (B) (C) (D) (E) 3. 3 4 5 6 7 original fraction. 3 The value of a certain fraction is . If both the 5 numerator and denominator are increased by 5, the new fraction is equivalent to original fraction. (A) (B) (C) (D) (E) 3 5 6 10 9 15 12 20 15 25 7 . Find the 10 www.petersons.com 180 Chapter 12 6. MIXTURE PROBLEMS There are two kinds of mixture...
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This note was uploaded on 08/15/2010 for the course MATH a4d4 taught by Professor Colon during the Spring '10 term at Embry-Riddle FL/AZ.

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