原式=-a(a^2-2a+1)
=-a(a-1)^2
=(2a的2β-1)(3)χ^ 4-y的^ 4 =(X + Y)(XY)=(X + y)的(x + y的)(XY)(4)-2一^ 2 ^ 3 =(1-2a的+)=-?(1-a)的..
=(图2a +2 b的-1)(3)χ^ 4-γ^ 4 =(x + y的)值(xy)=(X + y)的(x + y的)(xy)的(4)-α2一^ 2 ^ 3 =-α-(1-2a的+)=-?(1-a)的..
-a+2a^2-a^3
=-a(1-2a+a²)
=-a(1-a)²
原配方=-A(A ^ 2-2A +1) =(A-1)^ 2