Ответ : 1)60, 2) 3, 3)20 4),150
(x - 1/2 - 4i)(x - 1/2 + 4i) = x^2 - x/2 - x*4i - x/2 + 1/4 + 2i + x*4i - 2i - (4i)^2 = 0
Упрощаем
x^2 - x + 1/4 - 16i^2 = x^2 - x + 1/4 + 16 = x^2 - x + 65/4 = 0
Умножаем на 4
4x^2 - 4x + 65 = 0
<span>287² - 287 * 48 + 239 * 713 = </span>239000
287*287=82369
287*48=13776
239*713=170407
82369 - 13776= 68593
68593+170407=239000
<span>73,4² + 73,4 * 17,2 - 90,6 * 63,4 = 906
73,4*73,4= 5387,56
73,4*17,2=1262,48
90,6*63,4=5744,04
5387,56+1262,48=6650,04
6650,04-5744,04=906
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