Respuesta :

Answer:  −3.5

Step-by-step explanation:

Standard form:

4x2 + 28x + 49 = 0

Factorization:

(2x + 7)2 = 0

Answer equation: 2x + 7 = 0  ⇒ x1 = x2 = −7  over 2   = −3.5