Question #0172a

1 Answer
Oct 10, 2017

A rational number "is any number that can be expressed as the quotient or fraction #p/q# of two integers, a numerator #p# and a non-zero denominator #q#. Since #q# may be equal to #1#, every integer is a rational number" (Wikipedia).

Explanation:

The numbers given to us have a bar on the top. In case you don't know what that means, if we translate number #21# we get this:

#-0.11111111111111...#(extending until infinite #1#'s)

So, is this a rational number? Yes, because you can (as the definition from Wikipedia states), #-0.1111111111111111...# can also be expressed as the fraction #-1/9#, where #p=-1# and #q=9#.

Similarily, you will find number #22# to also be expressed as a fraction. I will not show the process here because you probably get the point.

Therefore, both number #21# and #22# are rational numbers.

I hope that helps!