X2 + 6x + 5 = 0
D = b2 - 4ac = 62 - 4·1·5 = 36 - 20 = 16x1 = -6 - √16 /2·1 = -6 - 4 /2 = -10 /2 = -5x2 = -6 + √16 /2·1 = -6 + 4 /2 = -2 /2 = -1
x2 - 6x - 11 = 0
D = b2 - 4ac = (-6)2 - 4·1·(-11) = 36 + 44 = 80x1 = 6 - √80/2·1 = 3 - 2√5 ≈ -1.4721359549995796x2 = 6 + √80 /2·1 = 3 + 2√5 ≈ 7.47213595499958