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