X^2 + 5x = -6
Add 6 to both sides:
X^2 + 5x + 6 = 0
Using the quadratic equation x = -b +/-sqrt(b^2 -4ac )/2a replace the letters with their values and solve for x.
A = 1, b = 5 , c = 6
Solving for x you get -2 and -3
The answer would be x = -3 and x = -2