Question 131409
SOLUTION - 

          X^2 + X - 12 = 0

          X^2 + 4X - 3X - 12 = 0
                           
          X(X + 4) - 3(X + 4) = 0
                 
          (X - 3)(X + 4) = 0

              X - 3 = 0
               
                 X = 3

              X + 4 = 0

                 X = -4