因式分解4x(2x-y)+2y(y-2x)
=4x(2x-y)-2y(2x-y)
=2(2x-y)(2x-y)
=2(2x-y)^2
9*10^2008-10^2009=
=9*10^2008-10*10^2008
=(9-10)*10^2008
=-10^2008
因式分解6（x-y)^3+15（y-x)^2-9（y-x)^3
=6（x-y)^3+15（x-y)^2+9（x-y)^3
=15（x-y)^3+15（x-y)^2
=15(x-y)^2(x-y+1)
(5-2x)^2+（2x+5)(5-2x)
=(5-2x)(5-2x+2x+5)
=10*(5-2x)
=10*(5-2*2008)
=10*(-4011)
=-40110