Step 1 :
Rewrite $ x^{10}-1 $ as:
$$ x^{10}-1 = (x^{5})^2 - (1)^2 $$Now we can apply the difference of squares formula.
$$ I^2 - II^2 = (I - II)(I + II) $$After putting $ I = x^{5} $ and $ II = 1 $ , we have:
$$ x^{10}-1 = (x^{5})^2 - (1)^2 = ( x^{5}-1 ) ( x^{5}+1 ) $$Step 2 :
To factor $ x^{5}-1 $ we can use formula:
$$ I^5 - II^5 = (I - II)(I^4 + I^3 \cdot II + I^2 \cdot II^2 + I \cdot II^3 + II^4) $$After putting $ I = x $ and $ II = 1 $ , we have:
$$ x^{5}-1 = ( x-1 ) ( x^{4}+x^{3}+x^{2}+x+1 ) $$Step 3 :
To factor $ x^{5}+1 $ we can use formula:
$$ I^5 + II^5 = (I + II)(I^4 - I^3 \cdot II + I^2 \cdot II^2 - I \cdot II^3 + II^4) $$After putting $ I = x $ and $ II = 1 $ , we have:
$$ x^{5}+1 = ( x+1 ) ( x^{4}-x^{3}+x^{2}-x+1 ) $$