已知m的平方=25,|n|=0.2,|m-n|=n-m.求：（1)m,n的值；（2）代数式m的2004幂方*n的2005

m的平方=25,
m=±5
|n|=0.2
n=±0.2
|m-n|=n-m
n>m
即m=-5
所以m=-5,n=±0.2
2.
当m=-5,n=0.2时
m^2004*n^2005
=m^2004*n^2004*n
=(mn)^2004*n
=(-5*0.2)^2004*0.2
=(-1)^2004*0.2
=1*0.2
=0.2
当m=-5,n=-0.2时
m^2004*n^2005
=m^2004*n^2004*n
=(mn)^2004*n
=[-5*(-0.2)]^2004*(-0.2)
=1^2004*(-0.2)
=1*(-0.2)
=-0.2