Question

identify the number that does not belong with the other three. Explain your reasoning.
@mathstudent55

Answer 1

i think it 13.4

Answer 2

I think this question deals with sets of numbers.
Have you learned the sets of numbers called:
Natural Numbers
Whole Numbers
Rational Numbers
Irrational Numbers
Real Numbers

Answer 3

its hard for me to understand math.

Answer 4

Natural numbers: 1, 2, 3, 4, 5, ...
Whole numbers: 0, 1, 2, 3, 4, 5, ...
Integers: ..., -3, -2, -1, 0, 1, 2, 3, ...
Rational Number: Any number that can be written as a fraction of integers
Irrational Number: a number that is not rational
Real Numbers: the set containing all rational and irrational numbers

Answer 5

Look at each number and see which sets it belongs to.

Answer 6

okay 22.7 belongs to rational numbers?
-13.4 belongs to integers?
-10/2 belongs to rational?
22.7 belongs to integers.

Answer 7

-10/2 = -5
-5 is an integer and is rational

Answer 8

-13.4 is not an integer, but it is rational. It can be written as -134/10, for example.

Answer 9

oh yeah! oh my! i forgot you can add a 0 to any 1 with rational numbers.

Answer 10

22.777... (the bar over the seven means the seven repeats).
This is a rational number. Any repeating decimal can be written as a fraction of integers.

Answer 11

i think its 18 that doesnt belong there.

Answer 12

That leaves \(\sqrt{18} \).
This can be simplified like this:
\(\sqrt{18} = \sqrt{9 \times2} = \sqrt 9 \times \sqrt 2 = 3\sqrt{2}\)
The square root of 2 is not a rational number, so \(\sqrt{18} \) is an irrational number.

Answer 13

You are right.
All other numbers are rational.
\(\sqrt{18} \) is the only irrational number in the group.

Answer 14

yes! you made me understand! Thank you very much! Do you mind helping me with 4 more questions? @mathstudent55

Answer 15

Ok, but I need to go in about 5 minutes.
Start a new post with one, and we'll do it together.

Answer 16

yay! okay! @mathstudent55