①x^n+1*x^n-1 ②[(x+1/2y)^2+(x-1/2y)^2](2x^2-1/2y^2) ③(a-b)^2n+2+(a-b)^2n 因式分解
问题描述:
①x^n+1*x^n-1 ②[(x+1/2y)^2+(x-1/2y)^2](2x^2-1/2y^2) ③(a-b)^2n+2+(a-b)^2n 因式分解
答
x²-2xy+y²-2x+2y+1=(x-y)²-2(x-y)+1=(x-y-1)²-x^(n+1)+2x^n-x^(n-1)=-x^(n-1)*x^2+2x^(n-1)*x-x^(n-1)=-x^(n-1)[x^2-2x+1]=-x^(n-1)(x-1)^21998×2000-1999² =(1999-1)(1999+1)-1999²...