(x+y)^2-10(x+y)^2+25

(x+y)^2-10(x+y)^2+25


(x+y)^2-10(x+y)^2+25
=25-9(x+y)^2
=(5-3x-3y)(5+3x+3y)



25(x-y)2+10(y-x)+1.


25(x-y)2+10(y-x)+1=[5(x-y)]2-2×1×5(x-y)+12=[5(x-y)-1]2=(5x-5y-1)2.



分解因式(x一y)的平方一8(x一y)十16
(2a一3b)的平方一4(a十b)的平方(a一2b)的平方十8ab


(x一y)的平方一8(x一y)十16=(x-y-4)²;(2a一3b)的平方一4(a十b)的平方=[(2a-3b)+2(a+b)][(2a-3b)-2(a+b)]=-5b(4a-b)(a一2b)的平方十8ab=a²;-4ab+4b²;+8ab=a²;+4ab+4b²;=(a+2b)²;…