X^2-4X-96=0

2X^2+8X-24=0

-X^2+3X+18=0

X^2-4X-96=0

Δ=4^2-4*1 * (-96) = 16+384=400

√Δ=20

X1 = (4+20) / 2*1=24/2=12

Х2 = (4-20) / 2*1=-16/2=-8

2X^2+8X-24=0

Δ=8^2-4*2 * (-24) = 64+192=256

√Δ=16

Х1 = (-8+16) / 2*2=8/4=2

Х2 = (-8-16) / 2*2=-24/2=-12

-X^2+3X+18=0

Δ=3^2-4 * (-1) * 18=9+72=81

√Δ=9

Х1 = (-3+9) / (-1) * 2=6 / (-2) = - 3

X2 = (-3-9) / (-1) * 2=-12 / (-2) = 6