因式分解:a^(n+2)-4a^(n+1)+4a^n

问题描述:

因式分解:a^(n+2)-4a^(n+1)+4a^n

=an+2a-4an-4a+4an
=an-2a
=a(n-2)

4(a-2)^2a^n

a^(n+2)-4a^(n+1)+4a^n
=a^n(a^2-4a+4)
=a^n(a-2)^2