х² + 11х + q = 0,
(-7)² + 11*(-7) + q = 0,,
49 - 77 + q = 0,
q = 77 - 49,
q = 28,
х² + 11х + 28 = 0,
Д = 11² - 4*1*28 = 121 - 112 = 9,
х2 = (-11 + 3) / 2*1 = -8/2 = -4
х² + 11х + q = 0,
(-7)² + 11*(-7) + q = 0,,
49 - 77 + q = 0,
q = 77 - 49,
q = 28,
х² + 11х + 28 = 0,
Д = 11² - 4*1*28 = 121 - 112 = 9,
х2 = (-11 + 3) / 2*1 = -8/2 = -4