Chapter 10 - Radical Expressions and Equations - 10-4 Solving Radical Equations - Practice and Problem-Solving Exercises - Page 623: 16

$x=19$

$Given,$ $\sqrt (x-3)=4 $ Squaring,we get: $x-3=16$ $x-3+3=16+3$ $x=19$ We need to check by putting the obtained value in the original equation : $L.H.S=\sqrt (19-3)=\sqrt 16=4=R.H.S$ Hence,$x=19$ is a valid solution