Respuesta :

Step-by-step explanation:

x²+8x+15=0

x²+8x=-15

x²-8x+(8×½)²=-15+(8×½)

(x-8/2)²=-15+64/4

(x-8/2)²=4/4

take the square root of both sides

x-8/2=±√4/4

x-8/2±2/2

x=8/2+2/2 or 8/2-2/2

x=10/2 or 6/2

x=5 or 3 ans