let x and y be irrational number.
then, take
[tex]x=\sqrt[]{5\text{ }}and\text{ y=}\sqrt[]{5}[/tex]therefore,
[tex]\begin{gathered} xy=\sqrt[]{5}\times\sqrt[]{5} \\ =5 \end{gathered}[/tex]5 is a rational number.
we have disproved the given statement.
