Question

(7x-1)(x-1)=16
Пожалуйста

Answer 1

$(7x - 1)(x - 1) = 16 \ 7x {}^{2} - 7x - x + 1 = 16 \ 7x {}^{2} - 8x + 1 - 16 = 0 \ 7x {}^{2} - 8x - 15 = 0 \ d = b {}^{2} - 4ac =( - 8) {}^{2} - 4 times 7 times ( - 15) = 64 + 420 = 484 : : : (22) \ x = frac{ - b + - sqrt{d} }{2a} = frac{8 + - 22}{2 times 7} = frac{ - 14}{14} : : or : : frac{30}{14} = - 1 : : or : : frac{15}{7} = - 1 : : or : : 2 frac{1}{7}$

Ответ : -1; 2 1/7