Question

Розв'кжить рiвняння: a) (x-2) - x² = 12; б) (x+3)(x-3) - x² = 3x.​

Answer 1

Ответ:

$a)(x - 2) - {x}^{2} = 12 \\ x - 2 - {x}^{2} = 12 \\ x - 2 - {x}^{2} - 12 = 0 \\ - {x}^{2} + x - 14 = 0 \\ {x}^{2} - x + 14 = 0 \\ a = 1 \: \: \: b = - 1 \: \: \: c = 14 \\ d = {b}^{2} - 4ac \\ d = ( - 1 {)}^{2} - 4 \times 1 \times 14 = 1 - 56 = - 55$

х є 0

$b)(x + 3)(x \times - 3) - {x}^{2} = 3x \\ {x}^{2} - 3x + 3x - 9 - {x}^{2} = 3x \\ - 3x + 3x - 3x = 9 \\ - 3x = 9 \\ x = - 3$