Question

Hey Frnds !!

Plzz answer my question....

Plzz solve this question on copy...

thnx •_•

Answer 1

$x = \frac{1}{2 - \sqrt{3} } \\ 2x - x \sqrt{3} = 1 \\ x \sqrt{3} = 2x - 1 \\ squaring \: both \: sides \\ 3 {x}^{2} = 4 {x}^{2} + 1 - 4x \\ {x}^{2} - 4x + 1 = 0 \\ {x}^{2} = 4x - 1$

${x}^{3} - 2 {x}^{2} - 7x + 5 \\ = x(4x - 1) - 2 {x}^{2} - 7x + 5 \\ = 4 {x}^{2} - x - 2 {x}^{2} - 7x + 5 \\ = 2 {x}^{2} - 8x + 5 \\ = 2( {x}^{2} - 4x) + 5 \\ = 2( - 1) + 5 \\ = - 2 + 5 \\ = 3$