The difference of two rational numbers is rational. Let the two rational numbers be a/b and c/d, where a, b, c, and d are integers. Any rational number can be represented this way. Their difference is
Products and differences of integers are always integers. This means that ad-cb is an integer, and so is bd.
Thus, (ad-cb)/bd is a rational number (since it is the ratio of two integers). This is equivalent to the difference of the original two rational numbers.
Another rational number.
Yes, it must.
The rational numbers form a field. In particular, the sum or difference of two rational numbers is rational. (This is easy to check directly). Suppose now that a + b = c, with a rational and c rational. Since b = c - a, it would have to be rational too. Thus you can't ever have a rational plus an irrational equalling a rational.
There is no number which can be rational and irrational so there is no point in asking "how".
It is a rational number.
Yes. This is the same as asking for one rational number to be subtracted from another; to do this each rational number is made into an equivalent rational number so that the two rational numbers have the same denominator, and then the numerators are subtracted which gives a rational number which may possibly be simplified.
Yes, that's true.
A rational number can be written as (one whole number) divided by (another whole number). An irrational number can't.
An example of a whole number would be this >>> 2 1/3 Except a real number would be any rational Or irrational number :)