Solving by Factoring |
EXPLANATIONS for x^{2} -4x - 12
The x intercepts are (6) and (-2). The symmetry axis is the line x = 2, with 2 being the midpoint between the intercepts. |

Concept Check:
The symmetry axis for the function y= 3x^{2}+18x is the sum of the x intercepts divided by 2, therefore: