Chapter 10 - Radical Expressions and Equations - 10-4 Solving Radical Equations - Practice and Problem-Solving Exercises - Page 623: 10

$n=81$

$Given,$ $\sqrt n-3=6$ $\sqrt n-3+3=6+3$ $\sqrt n=9$ Squaring,we get: $n=81$ We need to check by putting the obtained value in the original equation : $L.H.S=\sqrt 81-3=9-3=6=R.H.S$ Hence, $n=81$ is a valid solution