Question

Решите уравнение:
(3x-7)(x+4)+(x-1)(x+4)=0.
Срочно!

Answer 1

(3х- 7)(х+4)+(х-1)(х+4)=0
${3x}^{2} + 12x - 7x - 28 + {x}^{2} + 4x - x - 4 = 0 \\ 4 {x}^{2} + 8x - 32 = 0 \\ {x}^{2} + 2x - 8 = 0 \\ d = 4 + 32 = 36 \\ \sqrt{d} = \sqrt{36} =6 \\ x1 = \frac{ - 2 + 6}{2} = 2 \\ x2 = \frac{ - 2 - 6}{2} = - 4$
Ответ: -4;2