Identify the characteristic equation for an=7an−1−12an−2a_n = 7a_{n-1} - 12a_{n-2}an=7an−1−12an−2.
r2+7r−12=0r^2 + 7r - 12 = 0r2+7r−12=0
r2−7r−12=0r^2 - 7r - 12 = 0r2−7r−12=0
r2+7r+12=0r^2 + 7r + 12 = 0r2+7r+12=0
r2−7r+12=0r^2 - 7r + 12 = 0r2−7r+12=0