One more confusing factoring question. The question is:

$x^6 + 5x^3 + 8$

Please can someone help me in factorising this. I saw some solutions but they are not meant for a IX grade student. 
Thanks for the help.

We can rearrange the polynomial as follows and use a difference of cubes:
\begin{align*}
x^6+5x^3+8&=(x^2+2)^3-6x^4+5x^3-12x^2\\
&=(x^2+2)^3-x^3-x^2(6x^2-6x+12)\\
&=\left[(x^2+2)-x\right]\left[(x^2+2)^2+x(x^2+2)+x^2\right]-6x^2(x^2-x+2)\\
&=(x^2-x+2)\left[(x^2+2)^2+x(x^2+2)-5x^2\right]\\
&=(x^2-x+2)\left(x^4+x^3-x^2+2x+4\right)\\
\end{align*}
