Question

Реши уравнение и сделай проверку:
(х-4)^2 = 9(8-х)

Answer 1

$x ^{2} - 8x + 16 - 72 + 9x = 0 \\ x ^{2} + x - 56=0 \\ d = 1 + 224 = 225 \\ x1 = \frac{ - 1 + \sqrt{225} }{2} = 7 \\ x2 = \frac{ - 1 - \sqrt{225} }{2} = - 8 \\ (7 - 4)^{2} = 9(8 - 7) \\ 9 = 9 \\ ( - 8 - 4)^{2} = 9(8 + 8) \\ 12 = 12$