Nokea
What is the domain for the function f(x)=2x+5?
- A. All real numbers
- B. x ≥ 0
- C. x > 0
- D. x ≤ 0
Correct Answer: A
Rationale: The domain of a function represents all possible input values that the function can accept. In this case, the function f(x)=2x+5 is a linear function, and linear functions have a domain of all real numbers. This means that any real number can be substituted for x in the function f(x)=2x+5, making choice A, 'All real numbers,' the correct domain for this function. Choices B, C, and D, restrict the domain unnecessarily by limiting the values of x to specific subsets of real numbers, which does not accurately reflect the nature of the given function.
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Express as an improper fraction: 8 3/7
- A. 11/7
- B. 21/8
- C. 5/3
- D. 59/7
Correct Answer: D
Rationale: To convert the mixed number 8 3/7 to an improper fraction, multiply the whole number (8) by the denominator (7) and add the numerator (3) to get the numerator of the improper fraction. This gives us (8*7 + 3) / 7 = 59/7. Therefore, the correct answer is 59/7. Choice A (11/7), choice B (21/8), and choice C (5/3) are incorrect because they do not correctly convert the mixed number to an improper fraction.
In the problem 6 + 3 2, which operation should be completed first?
- A. Multiplication
- B. Addition
- C. Division
- D. Subtraction
Correct Answer: A
Rationale: The correct answer is 'Multiplication.' According to the order of operations (PEMDAS), which stands for Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right), multiplication should be completed first. In the given expression, 3 2 should be solved before adding 6 to the result. This means that the multiplication operation should be prioritized over addition. Choices B, C, and D are incorrect because, in the order of operations, multiplication takes precedence over addition, division, and subtraction, respectively.
A closet is filled with red, blue, and green shirts. If 2/5 of the shirts are green and 1/3 are red, what fraction of the shirts are blue?
- A. 4/15
- B. 1/5
- C. 7/15
- D. 1/2
Correct Answer: C
Rationale: To find the fraction of blue shirts, subtract the fractions of green and red shirts from 1. Green shirts are 2/5 and red shirts are 1/3, which sum up to 11/15. Therefore, blue shirts would be 1 - 11/15 = 4/15. So, the correct answer is 4/15. Choice A (4/15) is incorrect as it represents the overall fraction of green shirts. Choice B (1/5) is incorrect as it does not account for the fractions of green and red shirts. Choice D (1/2) is incorrect as it does not consider the given fractions of green and red shirts.
Express 18/5 as a reduced mixed number.
- A. 3 3/5
- B. 3 1/15
- C. 3 1/18
- D. 3 1/54
Correct Answer: A
Rationale: To convert the improper fraction 18/5 to a mixed number, divide 18 by 5. The quotient is 3 with a remainder of 3, which translates to 3 3/5. Therefore, the correct answer is A. Choices B, C, and D are incorrect because they do not accurately represent the conversion of 18/5 to a mixed number.
How should 0.80 be written as a percent?
- A. 40%
- B. 125%
- C. 90%
- D. 80%
Correct Answer: D
Rationale: To convert a decimal to a percent, move the decimal point two places to the right. Therefore, 0.80 written as a percent is 80%. Choice A is incorrect as it represents 40%. Choice B is incorrect as it represents 125%. Choice C is incorrect as it represents 90%.