## anonymous one year ago To which subsets of real numbers does the number -22 belong? Choose all subsets that apply. theres only 2 btw A.Whole Numbers B.Rational Numbers C.Integers D.Irrational Numbers E.Natural Numbers

1. mathstudent55

Natural Numbers (also called Counting Numbers): 1, 2, 3, 4, 5, ... Whole Numbers: 0, 1, 2, 3, 4, 5, ... Integers: ..., -3, -2, -1, 0, 1, 2, 3, ... Rational Number: a number that can be written as a fraction of integers Irrational Number: a number that is not rational

2. anonymous

hmm

3. mathstudent55

Go through each definition, and see if -22 belongs in each set. Notice that the definitions are not in the same order as your choices.

4. anonymous

okay so the first is integers but i dont understand what the second one would be

5. anonymous

?

6. anonymous

the first is integers but i dont know the second one

7. mathstudent55

-22 is definitely an integer, but it is part of another set in the choices too.

8. anonymous

irrational numbers?

9. mathstudent55

No. Look at the definition of rational. Can -22 be written as a fraction with an integer in the numerator and an integer in the denominatior?

10. mathstudent55

For example, $$\dfrac{-22}{1}$$ Is this fraction equal to -22? Are -22 and 1 integers?

11. anonymous

Hmm so is it rational?

12. mathstudent55

Correct. -22 can be written as a fraction of integers in may ways. Here is another way: $$\dfrac{-44}{2}$$ -44 and 2 are both integers, and that fraction equals -22, so -22 is a rational number.

13. anonymous

Awesome :D

14. anonymous

Is it okay if i copy and paste ur notes to my notebook? for learning

15. mathstudent55

Yes, be my guest. Your problem is already answered, but for a little more understanding, read on. Now we can ask a question. Then what is an irrational number? A number such as $$\pi$$ which is the circumference divided by the diameter of a circle. $$\sqrt 2$$, $$\sqrt 3$$ These numbers cannot be written as a fraction of integers. You may have seen an approximation of $$\pi$$ written as $$\dfrac{22}{7}$$, but that is only a rational approximation. $$\pi$$ is an irrational number.

16. anonymous

Okay well thank you for your help :)

17. mathstudent55

You're welcome.