Решите уравнение: а)3x^2+9=12x-x^2 б)5x^2+1=6x-4x^2 в)x(x+2)-3 г)x(x+3)=4 д)x(x-5)=-4 е)x(x-4)=-3 ж)x(2x+1)=3x+4 з)x(2x-3)=4x-3

1) 3x² + 9 - 12x + x² = 0 4x² - 12x + 9 = 0 D = b² - 4ac = 144 - 16×9 = 0 x = -b/2a x = 12/8 x = 1,5 2) 5x² + 1 - 6x + 4x² = 0 9x² - 6x + 1 = 0 D = b² - 4ac = 36 - 36×1 = 0 x = -b/2a x = 6/18 x = 1/3 3) x² + 2x - 3 = 0 D = b² -4ac = 4 - 4×(-3) = 26 = 4² x1 = ( - 2 + 4) / 2 = 1 x2 = ( - 2 - 4) / 2 = - 3 4) x² + 3x -4 = 0 D = b²- 4ac = 9 - 4×(-4) = 25 = 5² x1 = ( - 3 + 5) / 2 = 1 x2 = ( - 3 - 5) / 2 = - 4 5) x² - 5x + 4 = 0 D = b² - 4ac = 25 - 4×4 = 9 = 3² x1 =( 5 + 3) / 2 = 4 x2 = ( 5 - 3) / 2 = 1 6) x² - 4x + 3 = 0 D = b - 4ac = 16 - 4×3 = 4 = 2² x1 = ( 4 + 2) / 2 = 3 x2 = ( 4 - 2) / 2 = 1 7) 2x² + x - 3x - 4 = 0 2x² - 2x - 4 = 0 x² - x - 2 = 0 D = b² - 4ac = 1 - 4×(-2) = 9 = 3² x1 = ( 1 + 3) / 2 = 2 x2 = ( 1 - 3) / 2 = - 1 8) 2x² - 3x - 4x + 3 = 0 2x² - 7x + 3 = 0 D = b²- 4ac = 49 - 8×3 = 25 = 5² x1 = ( 7 + 5) / 4 = 3 x2 = ( 7 - 5)/ 4 = 0,5