因式分解的难题！！！怎么解？？

已知X=2007,求(5-2X)^2+(2X+5)(5-2X)的值
(5-2X)^2+(2X+5)(5-2X)
= (5-2X)*[(5-2X)+(5+2X)]
=(5-2X)*10
=(5-2*2007)*10
=(5-4014)*10
=-4009*10
=-40090

(b－a)^3－3(b－a)+2
(b－a)^3－3(b－a)+2

=(b－a)^3-1－3(b－a)+3

=(b-a-1)[(b-a)^2+(b-a)+1]-3(b-a-1)

=(b-a-1)[(b-a)^2+(b-a)+1-3]

=(b-a-1)[(b-a)^2+(b-a)-2]

=(b-a-1)(b-a+2)(b-a-1)

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

一种直接分解
(5-2X)^2+(2X+5)(5-2X)
= (5-2X)*[(5-2X)+(5+2X)]
=(5-2X)*10

二种先去括号再分解
(5-2X)^2+(2X+5)(5-2X)
=25-20X+4X^2+25-4X^2
=50-20X
=10(5-2X)
然后再带入求值

把后面（5-2X）加个-，前面加号改减号