分解因式:-9x^(n+1)-6x^n+3x^(n-1)
-9x^(n+1)- 6x^n + 3x^(n-1)
= -3x^(n - 1)·(3x²;+ 2x - 1)
= -3x^(n - 1)·(3x - 1)(x + 1)
分解因式-3x^2+12x-12
-3x^2+12x-12
=-3(x^2-4x+4)
=-3(x-2)^2
分解因式12x^2-3x
12x^2-3x
=3(4x^2-1)
=3(2x+1)(2x-1)