Which expression is irrational?

Answer:
[tex]\sqrt{50}[/tex]
Step-by-step explanation:
An irrational number is a number that isn't a whole number (integer).
[tex]\sqrt{50}[/tex] = 7.07
[tex]\sqrt{1}[/tex] = 1
[tex]\sqrt{25[/tex] = 5
[tex]\sqrt{9}[/tex] = 3
The first one is the only one that isn't an integer. So it is the answer.