Question

Multiply the surd $(\sqrt{5}+\sqrt{2})$ by _____ to get a rational number.

Answer 1

Solution:

Rationalisation of surd $(\sqrt{5}+\sqrt{2})$

$(\sqrt{5}+\sqrt{2})\times (\sqrt{5}-\sqrt{2})$

$=(\sqrt{5}{)}^2-(\sqrt{2}{)}^2$

$=5-2$

$=3$