Ответы и объяснения

2013-05-17T14:49:11+00:00

x^2 - 5x - 36 = (x-9)(x+4)

x^2-5x-36 = 0

D = 25-4*(-36) = 25+144 = 169 = 13^2

x1 = 5+13/2 = 9

x2 = 5-13/2 = -4