Solve the quadratic equation by using either a numeric or a graphic approach.
x2 - 12x – 144 = 0
a. x= -12.4 or x = -7.4
c. x = 9.4 or x = -7.5
b. x = 19.4 or x = -7.4
d. x = 9.4 or x = -3.4