因式分解（x+y-2xy)(x+y-2)+(xy-1)^2设x+y=a,xy=b,_数学解答

因式分解（x+y-2xy)(x+y-2)+(xy-1)^2
设x+y=a,xy=b,

人气：263 ℃　时间：2019-10-09 13:17:07

解答

(a-2b)(a-2)+(b-1)^2
=a^2-2ab-2a+4b+b^2-2b+1
=a^2-2ab-2a+b^2+2b+1
=a^2-2ab+b^2-2a+2b+1
=(a-b)^2-2(a-b)+1
=(a-b-1)^2