Answer:
[tex]-\left(x-1\right)\left(x^2+1\right)[/tex]
Step-by-step explanation:
[tex]1 - x + x^2 -x^3\\\\\mathrm{Factor\:out\:common\:term\:}-1\\\\=-\left(x^3-x^2+x-1\right)\\\\\mathrm{Factor}\:x^3-x^2+x-1:\quad \left(x-1\right)\left(x^2+1\right)\\\\=-\left(x-1\right)\left(x^2+1\right)[/tex]
