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Unformatted text preview: the first, in a bank paying 6% interest. If her annual income from both investments was $50, how much money did she invest at 6%? Solution: Represent the two investments algebraically. x = amount invested at 4% x – 500 = amount invested at 6% .04x = annual interest from 4% investment .06(x – 500) = annual interest from 6% investment .04x + .06(x – 500) = 50 Multiply by 100 to remove decimals.
4 x + 6 ( x − 500 ) = 5000 4 x + 6 x − 3000 = 5000 10 x = 8000 x = 800 x − 500 = 300 She invested $300 at 6%. www.petersons.com Problem Solving in Algebra 177 Exercise 4
Work out each problem. Circle the letter that appears before your answer. 1. Barbara invested x dollars at 3% and $400 more than this amount at 5%. Represent the annual income from the 5% investment. (A) .05x (B) .05 (x + 400) (C) .05x + 400 (D) 5x + 40000 (E) none of these Mr. Blum invested $10,000, part at 6% and the rest at 5%. If x represents the amount invested at 6%, represent the annual income from the 5% investment. (A) 5(x – 10,000) (B) 5(10,000 – x) (C) .05(x + 10,000) (D) .05(x – 10,000) (E) .05(10,000 – x) Dr. Kramer invested $2000 in an account paying 6% interest annually. How many more dollars must she invest at 3% so that her total annual income is 4% of her entire investment? (A) $120 (B) $1000 (C) $2000 (D) $4000 (E) $6000 4. Marion invested $7200, part at 4% and the rest at 5%. If the annual income from both investments was the same, find her total annual income from these investments. (A) $160 (B) $320 (C) $4000 (D) $3200 (E) $1200 Mr. Maxwell inherited some money from his 1 1 father. He invested of this amount at 5%,
2 2. 5. of this amount at 6%, and the rest at 3%. If the total annual income from these investments was $300, what was the amount he inherited? (A) (B) (C) (D) (E) $600 $60 $2000 $3000 $6000 3 3. www.petersons.com 178 Chapter 12 5. FRACTION PROBLEMS
A fraction is a ratio between two numbers. If the value of a fraction is , it does not mean that the numerator is 4 3 and the denominator 4. The numerator and denominator could be 9 and 12,...
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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 EmbryRiddle FL/AZ.
 Spring '10
 Colon
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