2) x^2 -6x + 4
3) x^2 = (x - 6)^2 + (x - 3)^2
x^2 = x^2 - 12x + 36 + x^2 - 6x + 9
x^2 - 18x +45 = 0
D = 324 - 180 = 144 = 12^2
x = (18 + 12)/2 = 15
Сторона а = 15 - 6 = 9
Сторона b = 15 - 3 = 12
6) теорема Виета
x1x2 = -4
x1 + x2 = -10
x1^2 + x2^2 + 2*x1x2 = 100
2*x1x2 = -8
x1^2 + x2^2 -8 = 100
x1^2 + x2^2 = 92