Answer:
see explanation
Step-by-step explanation:
Given
[tex]\frac{20}{\sqrt{2} }[/tex]
To rationalise the denominator multiply the numerator and denominator by [tex]\sqrt{2}[/tex], that is
[tex]\frac{20(\sqrt{2}) }{\sqrt{2}(\sqrt{2}) }[/tex]
= [tex]\frac{20\sqrt{2} }{2}[/tex]
= 10[tex]\sqrt{2}[/tex]