3 Answers: A, C, F
real numbers, integers, rational numbers
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Explanation:
So far in your studies, every number is a real number. This is assuming your teacher hasn't introduced complex or imaginary numbers yet.
So that's why -12 is a real number.
Choice A is one of the answers
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The set of whole numbers is {0,1,2,3,4,...} so we aren't including negative values here, which rules out choice B. However, the set of integers does include negative values
{..., -3, -2, -1, 0, 1, 2, 3, ...}
That makes -12 an integer
Choice C is one of the answers
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The value -12 is not irrational because we can write it as a fraction of two integers. Eg: -12 = -12/1
This shows that -12 is rational and why choice F is one of the answers and allows us to rule out choice D.
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We can rule out choice E because the set of natural numbers is {1,2,3,4,...} basically the set of whole numbers but we kicked out 0.
