Решите уравнение (3+6x)(3x-9)=0 25 - X во 2 степени =0

( 3 + 6x)( 3x - 9) = 0 9x - 27 + 18x² - 54x = 0 18x² - 45x - 27 = 0 D = b² - 4ac = ( - 45)² - 4 × 18 × ( - 27) = 2025 + 1944 = 3969 = 63² x₁ = 45 + 63 / 36 = 108 / 36 = 3 x₂ = 45 - 63 / 36 = - 18 / 36 = - 0,5 25 - x² = 0 - x² + 25 = 0 x² - 25 = 0 D = b² - 4ac = 0 - 4 × 1 × ( - 25) = 100 = 10² x₁ = 0 + 10 / 2 = 5 x₂ = 0 - 10 / 2 = - 5