Question

x 3 + 6x 2 - 4x - 24

Answer 1

I want to believe that the equation you're giving has 3x but not x3. therefore if so follow the following steps:
6x2=12;
3x+4x=7x;
then carry out subtraction o the following(+12-24)= -12;
therefore 7x=12;
x=12/7;
x=1/1/7

Answer 2

That is not what my computer showed. sorry

Answer 3

x3+6x2-4x-24=0
x2(x+6)-4(x+6)=0
(x+6)(x2-4)=0
x+6=0 & x2-4=0
x=-6 & x2=4 implies x = 2 & x= -2