Respuesta :

Answer:

x1 = -4.872983346

x2 = 2.872983346

Step-by-step explanation:

Given:

x^2+2x+7=21

Subtract 21 on both sides to get the right side equal to 0:

x^2+2x-14=0

Use the quadratic formula:

x1 = -4.872983346

x2 = 2.872983346