-12x²-x+1<0

x³+x²-9x-9=0


Odpowiedź :

-12x²-x+1<0
Δ=1+48=49
x₁=1/4
x₂=-1/3
xnalezy (-1/3,1/4)

x³+x²-9x-9=0
x²(x+1)-9(x+1)=0
(x²-9)(x+1)=0
x=3 v x=-3 v x=-1