For this case, we must indicate which of the given roots is a rational number.
By definition, we have that, a rational number is that which can be represented as the quotient of two integers or an integer and a positive natural. In other words, a common fraction with numerator and denominator other than zero.
We divide:
[tex]\sqrt {360} = 18.97366596, \it\ is\ not\ rational.\\\sqrt {644} = 25.37715508, \it\ is\ not\ rational\\\sqrt {225} = 15,\ is\ rational. \frac {15} {1}\\\sqrt {122} = 11.04536102,\ it\ is\ not\ rational.[/tex]
Answer:
[tex]\sqrt {225} = 15[/tex]
