<s>[INST] Express $y= x^{3} - x^{2} - 5x - 3$ in its fully factorised form Don't know how to do this, please help. I have never done factorising cubic polynomials and don't know how to go about this 
 [/INST] $$x^3-x^2-5x-3=x^3+2x^2-3x^2-6x+x-3$$
$$x^3+2x^2+x-3x^2-6x-3=0$$
$$x(x^2+2x+1)-3(x^2+2x+1)=0$$
$$(x^2+2x+1)(x-3)=0$$
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