Step : Factorising the equation:
(x+3)2−4(x+3)−5=0
Let x+3=y
⇒y2−4y−5=0
⇒y2−5y+y−5=0 {factorizing left hand side}
⇒y(y−5)+1(y−5)=0
⇒(y−5)(y+1)=0
⇒y−5=0 or y+1=0
{Zero product rule}
⇒y=5 or y=−1
As y=x+3
⇒x+3=5 or x+3=−1
⇒x=2 or x=−4
Hence, the required answer is x=2 or x=−4