Решить 1) x(x^2-2)=x^3+8 2) (x+5)(x-4)-x^2+18=0 - вопрос №7801888122382542180373253 от Nastya3748 17.07.2020 05:29

Question

Алгебра: Решить 1) x(x^2-2)=x^3+8 2) (x+5)(x-4)-x^2+18=0 3) (x+7)(x--3)^2=53

Nastya3748 · Answer

1) x(x²-2) = x³ + 8x³ - 2x = x³ + 8-2x = 8x = -42) (x + 5)(x - 4) - x² + 18 = 0x² - 4x + 5x - 20 - x² + 18 = 0x = 23) (x + 7)(x - 7) - (x - 3)² = 53x² - 49 - (x² - 6x + 9) = 53x² - 49 - x² + 6x - 9 = 536x = 111x = 18.5...