Can be rational or irrational.
Yes
Sure. For example, the sum of:root(2) and: - root(2) is zero, which is rational.
No. Two irrational numbers can be added to be rational. For example, 1/3 + 2/3 = 3/3. 1/3 and 2/3 are both irrational, but 3/3 = 1, which is rational.
In between any two rational numbers there is an irrational number. In between any two irrational numbers there is a rational number.
Since the sum of two rational numbers is rational, the answer will be the same as for the sum of an irrational and a single rational number. It is always irrational.
Can be rational or irrational.
The sum of two rational numbers is rational.From there, it follows that the sum of a finite set of rational numbers is also rational.
They are always rational.
Not necessarily. The sum of two irrational numbers can be rational or irrational.
The sum of two irrational numbers may be rational, or irrational.
It may be a rational or an irrational number.
No - the sum of any two rational numbers is still rational:
Yes Yes, the sum of two irrational numbers can be rational. A simple example is adding sqrt{2} and -sqrt{2}, both of which are irrational and sum to give the rational number 0. In fact, any rational number can be written as the sum of two irrational numbers in an infinite number of ways. Another example would be the sum of the following irrational quantities [2 + sqrt(2)] and [2 - sqrt(2)]. Both quantities are positive and irrational and yield a rational sum. (Four in this case.) The statement that there are an infinite number of ways of writing any rational number as the sum of two irrational numbers is true. The reason is as follows: If two numbers sum to a rational number then either both numbers are rational or both numbers are irrational. (The proof of this by contradiction is trivial.) Thus, given a rational number, r, then for ANY irrational number, i, the irrational pair (i, r-i) sum to r. So, the statement can actually be strengthened to say that there are an infinite number of ways of writing a rational number as the sum of two irrational numbers.
Yes
Yes. The sum of two irrational numbers can be rational, or irrational.
Yes, Rational numbers are numbers that can be written as a fraction. Irrational numbers cannot be expressed as a fraction.