AM-234

Surds and rationalising

A Math · Secondary 3 · Medium · Surds and rationalising

Express

\dfrac{7}{3+\sqrt{5}}

in the form

a + b\sqrt{5}

, where

a

and

b

are rational numbers.

$\dfrac{21}{4} - \dfrac{7}{4}\sqrt{5}$
$\dfrac{21}{4} + \dfrac{7}{4}\sqrt{5}$
$\dfrac{7}{4} - \dfrac{21}{4}\sqrt{5}$
$\dfrac{7}{3} - \dfrac{7}{3}\sqrt{5}$

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