Start by writing the radicals as decimal numbers
[tex]\begin{gathered} \sqrt[]{9}=3 \\ \sqrt[]{10}=3.162277\ldots \\ \sqrt[]{21}=4.582575\ldots \end{gathered}[/tex]
A rational number is one that can be written as a decimal number or a fraction without changing the corresponding value.
the only rational number is √9 since √10 and√21 cannot be writen as fractions in order to be called as a rational.
[tex]undefined[/tex]
