Answer:
see explanation
Step-by-step explanation:
Given
[tex]\frac{2}{5\sqrt{3} }[/tex]
To rationalise the denominator, multiply the numerator/ denominator by [tex]\sqrt{3}[/tex]
= [tex]\frac{2\sqrt{3} }{5\sqrt{3}(\sqrt{3}) }[/tex]
= [tex]\frac{2\sqrt{3} }{15}[/tex]
-----------------------------------------------------------------------
Given
[tex]\frac{\sqrt{5}+2 }{\sqrt{5}-2 }[/tex]
Multiply the numerator/ denominator by the conjugate of the denominator.
The conjugate of [tex]\sqrt{5}[/tex] - 2 is [tex]\sqrt{5}[/tex] + 2 , then
= [tex]\frac{(\sqrt{5}+2)(\sqrt{5}+2) }{(\sqrt{5}-2)(\sqrt{5}+2) }[/tex] ← expand numerator/denominator using FOIL
= [tex]\frac{5+4\sqrt{5}+4 }{5-4}[/tex]
= [tex]\frac{9+4\sqrt{5} }{1}[/tex]
= 9 + 4[tex]\sqrt{5}[/tex]
