Решите уравнения 1)х^2+3x+2=0. 2)-х^2-2х+24=0. 3) х^2-7х+12=0. 4)-х^2-5х+6=0

Question

Решите уравнения 1)х^2+3x+2=0. 2)-х^2-2х+24=0. 3) х^2-7х+12=0. 4)-х^2-5х+6=0

Answer 1

X² + 3x + 2 = 0
D = b² - 4ac = 9 - 4 × 2 = 1
x1 = ( - 3 + 1) / 2 = - 1
x2 = ( - 3 - 1) / 2 = -2

- x² - 2x + 24 = 0
x² + 2x ² - 24 = 0
D = b² - 4ac = 4 - 4 × (-24) = 4 + 96 = 100 = 10²
x1 = ( - 2 + 10) / 2 = 4
x2 = ( - 2 - 10) / 2 = - 6

x² - 7x + 12 = 0
D = b² - 4ac = 49 - 4 × 12 = 1
x1 = ( 7 + 1)/2 = 4
x2 = ( 7 - 1) / 2 = 3

- x² - 5x + 6 =0
x² + 5x - 6 = 0
D =b² - 4ac = 25 - 4 × ( - 6) = 49 = 7²
x1 = ( - 5 + 7) / 2 = 1
x2 = ( - 5 - 7)  / 2 = - 6