Question

Помогите плизз !¡!¡!

Answer 1

$8 x^{3} +4 x^{2} -18x-9=0 \ 8 x^{3} -18x+4 x^{2} -9=0 \ 2x(4 x^{2} -9)+1(4 x^{2} -9)=0 \ (4 x^{2} -9)(2x+1)=0 \ 4 x^{2} -9=0 \ 4 x^{2} =9 \ x^{2} = frac{9}{4} \ x= frac{3}{2} =1.5 \ x=- frac{3}{2} =-1.5\ 2x+1=0 \ 2x=-1 \ x=-0.5 \ \ 1.5*(-1.5)=-2.25$