√18
1) Looking at the numbers of that expression
[tex]\frac{-10}{-13.4}\text{ }\sqrt{18}+\text{ 22.7777}\ldots[/tex]So we have two Rational numbers and one Irrational, the only one that does not belong is, therefore, the Irrational one
Since √18 can't be written as a ratio since 18 is not a perfect square. There is not a rational number as the result of that radical
22.777....can be written as a ratio
And -10/-13.4 can be written as a ratio as well.
