What are similarities between, rational and irrational numbers?

Rational number are numbers which can be expressed in a ratio of two integers. Both numerator and denominator are whole numbers, where the denominator is not equal to zero.

An irrational number on the other hand is a number which cannot be expressed in a ratio of two integers. However there are similarities between them. For example: the product of both irrational numbers of born rational numbers can be rational number, both irrational and rational numbers can be negative and positive, and both can be expressed as a fraction.

A real number can be a rational number or an irrational number.

The rational numbers are those that can be expressed as the quotient of two integers.

Irrational numbers are the elements of the real line that can not be expressed by the quotient of two integers and are characterized by infinite non-periodic decimal figures.

As similarities we have:

1) Both numbers belong to the real numbers

2) Both numbers can be written as fractions

3) Both numbers can be positive or negative