Question

тест !!! + решение пж !!!!

Answer 1

9.
-x²-8x-12=0   I*(-1)
x²+8x+12=0   D=16
x₁=-2    x₂=-6.
10.
-x²-12x-24=0   I*(-1)
x²+12x+24=0   D=48
x₁=-6+2√3  x₂=-6-2√3.

Answer 2

$-x^2-8x-12=0 \\ D= 8^2-(-1)*(-12)*4=64+(-12)*4=64-48=16 \\ x_{1,2} = \frac{8+/-16^{1/2}}{-2} = \\ x_1 = -6 ; x_2 = -2 \\ \\ -x^2-12x-24=0 \\ D=12^2-(-1)*(-24)*4=144+(-24)*4=144-96=48 \\ x_{1,2} = \frac{12+/- \sqrt{48} }{-2} = \\ 48:2=24:2=12:2=6:2=3=2*sqrt(3) \\ x_1 = \frac{12+2* \sqrt{3} }{-2} = -6+2 \sqrt{3} ; x_2 = -6-2 \sqrt{3}$