Question

pls answer this questions
with explanation​

Answer 1

Answer:

I thin it is helpful to u.

Answer 2

Explanation:

$a = 1 + \sqrt{7}$

Therefore,

$\frac{-6}{a} = \frac{-6}{1 + \sqrt{7} }$

$=[ \frac{-6}{1 + \sqrt{7} } ][\frac{1-\sqrt{7} }{1 - \sqrt{7} } ]$$= \frac{-6(1 - \sqrt{7})}{1 - 7}$     [(a + b)(a - b) = a^{2} - b^{2}]

$= \frac{-6(1 - \sqrt{7})}{\\ - 6}$

$= 1 - \sqrt{7}$

Answer: $1 - \sqrt{7}$