Question

因式分解2题(10分) 明天交就要交!!急急急!!

要过程(包括答案)
1). x^ n+4-169^n+2 (n是自然数)
2). (1-x^2)(1-y^2)-4xy

拜托各位帮帮忙!!!

Answer 1

1). x^ n+4-169^n+2 是不是x^(n+4)-169^(n+2)?
x^(n+4)-169^(n+2)=[x^(n/2+2)]²-[13^(n+2)]²=[x^(n/2+2)+13^(n+2)]*[x^(n/2+2)-13^(n+2)]
2). (1-x^2)(1-y^2)-4xy=1-y²-x²+x²y²-4xy=1-2xy+(xy)²-(x²+2xy+y²)=(xy-1)²-(x+y)²
=(xy-1+x+y)(xy-1-x-y)

Answer 2

1)x^ (n+4)-169^(n+2)=(x-13)[x^ (n+3)+13x^(n+2)+13^2*x^(n+1)+13^3*x^n+。。。+13^（2n+3）】

2). (1-x^2)(1-y^2)-4xy=1-x²-y²+x²y²-4xy=(1-2xy+x²y²)-(x²-2xy+y²)=(1-xy)²-(x+y)²
=（1+x+y-xy)(1-x-y-xy).