Integers are counting numbers or include them.
1/2 is a rational number that is not a couinting number.
No, because the reverse statement may not result in a true statement.(A) If x is an integer then x*x is rational.(B) if x*x is rational then x is an integer.(B) is utter nonsense. x can be any rational number of even a square root of a rational number, for example, sqrt(2/3), and x*x will be rational.
No, all integers are rational, whole numbers.
Statement 1 is true but totally unnecessary. As integer is always a rational and you do not need to convert it to a fraction to determine whether or not it is rational. A negative fraction is can be rational or irrational. The fact that it is negative is irrelevant to its rationality. An integer number over a zero denominator is not defined and so cannot be rational or irrational or anything. It just isn't.
3.9
1/4 is an example.
Any fraction p/q where p is an integer and q is a non-zero integer is rational.
It is a number that can be expressed as a fraction but is NOT an integer. For example. 3 is an integer and it is rational since we can write 3/1, but 1/3 is not an integer and it is rational since we wrote it as a fraction or a ratio. Remember that a rational number is one that can be written as A/B where A and B are integers. Now if B is 1, which is certainly an integer, A/1 is rational but since A is an integer, A/1 is an integer.
Any negative integer.
"contrapositive" refers to negating the terms of a statement and reversing the direction of inference. It is used in proofs. An example makes it easier to understand: "if A is an integer, then it is a rational number". The contrapositive would be "if A is not a rational number, then it cannot be an integer". The general form, then, given "if A, then B", is "if not B, then not A". Proving the contrapositive generally proves the original statement as well.
It is rational and it is an integer.
It is a rational number, not an integer.
A rational number which is an integer can be simplified to a form in which the denominator is 1. That is not possible for a rational number which is not an integer.