Which of the following is the characteristic equation for an=5an−1−6an−2a_n = 5a_{n-1} - 6a_{n-2}an=5an−1−6an−2?
r2−5r+6=0r^2 - 5r + 6 = 0r2−5r+6=0
r2+5r−6=0r^2 + 5r - 6 = 0r2+5r−6=0
r2−6r+5=0r^2 - 6r + 5 = 0r2−6r+5=0
r2+6r−5=0r^2 + 6r - 5 = 0r2+6r−5=0