Answer:

x = -2 & -3

Step-by-step explanation:

x² + 5x + 6= 0

x² + 5x = -6

x² + 5x + 25/4 = -6 + 25/4

(x + 5/2) (x + 5/2) = 1/4

(x + 5/2)² = 1/4

✓(x + 5/2)² = ✓1/4

x + 5/2 = ±1/2

x = ±1/2 - 5/2

x = -4/2 & -6/2

x = -2 & -3