Question; Solve: $x + \sqrt{x^2 - 20} = 10$

Solution:
Given,

$x + \sqrt{x^2 - 20} = 10$

$or,  \sqrt{x^2 - 20} = 10-x$

[Squaring both sides]

$or, ( \sqrt{x^2 - 20})^2 = (10-x)^2$

$or, x^2 -20 = 10^2 - 2×10×x + x^2$

$or, x^2 - x^2 -20 = 100 - 20x$

$or, -20 = 100 - 20x$

$or, 20x = 100+20$

$or, x = \dfrac{120}{20}$

$\therefore x = 6$
= Answer