2+3x= -2x-13
3x+2x=-13-2
5x=-15
x=-15:5
x=-3
х³-5х²-6х=0
х(х²-5х-6)=0
х₁=0
х²-5х-6=0 D=25+24=49=7²
х₂=(5+7)/2=6
х₃=(5-7)/2=-1