Question

solve the following
x²+8x-11=0​

Answer 1

$\Huge{\red{\underline{\textsf{Answer}}}}$

$x = 4 + \sqrt{5} and$

$x = 4 - \sqrt{5}$

$\large{\red{\underline{\tt{Explanation}}}}$

x² - 2(x)(4) + (4)² - (4)² + 11 add and subtract (4)²

$\implies\rm (x - 4)^2 - 5 = 0$

$\implies\rm (x - 4)^2 = 5$

Taking sq root both sides :

√(x-4)²$= \sqrt{5}$

$x - 4 = \pm \sqrt{5}$

$x = 4\pm \sqrt{5}$

Therefore

$x = 4 + \sqrt{5}$

and

$x = 4 - \sqrt{5}$