New SAT Math Workbook

# Let a 4 r 2 and n 9 the number of terms in the

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Unformatted text preview: = 256, 000 a = 256, 000 ÷ 16 4 5. (B) Substitute the expression (x + 1) for x in 1 f , then combine terms: x 1 × f (x) 1 × f (x) 1 1 1+ x 1 f = = x x + 1 x x 6. (D) The question asks which number among the five listed is outside the function’s range. −x First, simplify the function. Note that 5 = a = 16, 000 1 , 5x Twenty years ago, Urbanville’s population was 16,000. 2. (E) The union of the three sets of factors is a set that contains all factors of any one or more of the three sets. The factors of 30 include all factors of 15, as well as the integer 6 and 30 (but not the integer 25). Choice (B) desribes the union of the factors of 15 and the factors of 30, but not the factors of 75 (which include 25). The factors of 75 include all factors of 15, as well as the integer 25 (but not integers 6 and 30). Choice (D) desribes the union of the factors of 15 and the factors of 75, but not the factors of 30 (which include 6 and 30). Thus, among answer choices (A) through (D), none describes the intersection of all three sets. (C) First, determine each of the three absolute values: |–1 – 2| = |–3| = 3 |5 – 6| = |–1| = 1 |–3 + 4| = |1| = 1 The combine the three results: 3 – 1 – 1 = 1. 4. (D) Multiply like base numbers by adding exponents, and divide like base numbers by subtracting the denominator exponent from the numerator exponent: x 6 y3 y yxx 63 and therefore that x 5− x = x 1 5x = ( x )(5x ) . To determine the function’s range, apply the rule that f(x) = (x)(5x) to each member of the domain, in turn: f (−2) = (−2)(5−2 ) = −2 2 =− 2 25 5 −1 1 f (−1) = (−1)(5−1 ) = 1 = − 5 5 f(0) = (0)(50) = (0)(1) = 0 f(2) = (2)(52) = (2)(25) = 50 The range of f(x) = x 2 1 is the set { − 25 , − 5 , 5− x 0, 50 }. Only answer choice (D) provides a number that is not in this range. 7. (B) To solve this problem, consider each answer choice in turn, substituting the (x,y) pairs provided in the question for x and y in the equation. Among the five equations, only the equation in c...
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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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