Решите уравнение: (x-9)²=-x²+15x+50 - вопрос №411420991550 от llllllllllllll1 30.04.2020 11:41

Question

Алгебра: Решите уравнение: (x-9)²=-x²+15x+50

llllllllllllll1 · Answer

(x -9)(x - 9) = -x² + 15x + 50x² - 9x - 9x + 81 = - x² + 15x + 50x² - 18x + 81 + x² - 15x - 50 = 02x² - 33x + 31 = 0D = b² - 4ac = ( - 33)² - 4 × 2 × 31 = 1089 - 248 = 841 = 29²x₁ = 33 + 29 / 2 × 2 = 62 /4 = 15,5x₂ = 33 - 29 / 4 = 4 / 4 = 1...