Решите уравнение (2x-1) (15+9x) - 6x (3x-5) = 87 (14x-1) (2+x) = (2x-8) (7x+1)

Решаем уравнения:

1) (2x - 1) (15 + 9x) - 6x (3x - 5) = 87;

30x + 18 х² - 15 - 9 х - 18 х² + 30x = 87;

51x - 15 = 87;

51x = 87 + 15;

51x = 102;

x = 102 / 51;

x = 2;

Проверка:

(2 x 2 - 1) (15 + 9 x 2) - 6 x 2 х (3 x 2 - 5) = (4 - 1) (15 + 18) - 12 х (6 - 5) = 3 х 33 - 12 = 99 - 12 = 87;

2) (14x - 1) (2 + x) = (2x - 8) (7x + 1);

28 х + 14x² - 2 - х = 14x² + 2x - 56x - 8;

28 х + 14x² - 14x² - х - 2x + 56x = 2 - 8;

81x = - 6;

x = - 6 / 81;

x = - 0,074;

Проверка:

(14 x ( - 0,074) - 1) (2 + ( - 0,074)) = (2 x ( - 0,074) - 8) (7 x ( - 0,074) + 1);

( - 1,036 - 1) (2 - 0,074) = ( - 0,148 - 8) ( - 0,518 + 1);

( - 2,036) х 1,926 = - 8,148 х 0,482;

- 3,92 = - 3,92.