Answer:
x = √5 - 1, and x = - √5 - 1; Option B
Step-by-step explanation:
See procedure below;
x^2 + 2x = 4,
( Write equation in form ) ⇒ x^2 + 2ax + a^2 = ( x + a )^2,
Solving for a; 2ax = 2x ⇒ a = 1,
x^2 + 2x + 1^2 = 4 + 1^2,
x^2 + 2x + 1^2 = 5,
( x + 1 )^2 = 5;
For f^2( x ) = a ⇒ solutions are √a, - √a,
x + 1 = √5, and x + 1 = - √5,
x = √5 - 1, and x = - √5 - 1;
Answer : x = √5 - 1, and x = - √5 - 1; Option B