Question

Can some one help me. The QN is SIMPLIFY BY RATIONALISING DENOMINATOR.

Answer 1

Answer:

$\frac{10}{3}$ - $\frac{2\sqrt{7} }{3}$

Step-by-step explanation:

Rationalise the denominator by multiplying the numerator/ denominator by the conjugate of the denominator

the conjugate of $\sqrt{7}$ + 5 is $\sqrt{7}$ - 5, hence

12 / ($\sqrt{7}$ + 5) × ($\sqrt{7}$ - 5 ) / ($\sqrt{7}$ - 5)

= (12$\sqrt{7}$ - 60 ) / - 18

= $\frac{10}{3}$ - $\frac{2\sqrt{7} }{3}$