Question

find the value of x in above question

Answer 1

Hello Mate!

What I did?

I first rationalize to fine x

Then I found value of x^3

Then I found 2x^2

Then 7x and arranged all.

Ping me out for any help.

Hope it helps☺!

Answer 2

HELLO.......FRIEND!!

THE ANSWER IS HERE,

$= > x = \frac{1}{2 - \sqrt{ 3} }$

$= > \: \frac{1}{2 - \sqrt{3} } \times \frac{2 + \sqrt{3} }{2 + \sqrt{3} }$

$= > \: \frac{2 + \sqrt{3} }{1}$

$= > \: 2 + \sqrt{3}$

From the question,

$= > \: {x}^{3} - 2 {x}^{2} - 7x + 5$

$= > ( {2 + \sqrt{3} )}^{3} - 2 ({2 + \sqrt{3})}^{2} - 7(2 + \sqrt{3} ) + 5$

$= > \: 8 + 3 \sqrt{3} + 12 \sqrt{3} + 18 - 2(4 + 3 + 4 \sqrt{3}) - 14 - 7 \sqrt{3} + 5$

$= > \: 26 + 15 \sqrt{3} - 14 - 8 \sqrt{3} - 14 - 7 \sqrt{3} + 5 .$

$= > \: 3 .$


:-)Hope it helps u.