✔ 最佳答案
Factorize.
y^(10n) - 2y^(5n) + 1
= [y^(5n)]^2 - 2y^(5n) + 1
Let y^(5n) = x.
x^2 - 2x + 1
= x^2 - x - x + 1
= (x^2 - x) - (x - 1)
= x(x - 1) - 1(x - 1)
= (x - 1)(x - 1)
Change x into y^(5n).
[y^(5n) - 1][y^(5n) - 1]
= [y^(5n) - 1]^2
We can know that the EXPRESSION y^(10n) - 2y^(5n) + 1 is a perfect square trinomial.