Question

please solve this problem

Answer 1

$\sqrt{20 + \sqrt{20 + \sqrt{20 +...... \infty } } } \\ let \: \infty \: be \: x \: then \\ \sqrt{20 + x} = 0 \\ on \: squaring \: both \: side \: we \: have: \\ 20 + x = 0 \\ x = - 20$