Question

How many unique values of x solve x2 + 4x + 4 = 0?

Answer 1

On the left side of equation is a perfect square trinomial:
 a² + 2 ab + b² = ( a + b )²
 x² + 4 x + 4 = 0
( x + 2 )² = 0
 x + 2 = 0
 x + 2 - 2 = 0 - 2
 x = - 2
Answer: There is one unique value of x.