Question

х²+9х+18=0 2х²-3х-5=0

Answer 1

x²+9x+18=0

D= 81-72=9

x1= (-9+3)/2= -3

x2= (-9-3)/2= -6

2x²-3x-5=0

D= 9+40= 49

x1= (3+7)/4= 2,5

x2= (3-7)/4= -1

Answer 2

1) D= 81-4*18=81-72=9=3

X1=-9+3/2=-6/2=-3

X2=-9-3/2=-6

Ответ -3; -6

2)D=9+8*5=49=7

Х1=3-7/4=-1

Х2=3+7/4=2,5

Ответ -1; 2,5