x=5,y=-1/5,n为自然数,求x^3n*x^3*y^2n*y^4的值如题..

x=5,y=-1/5,n为自然数,求x^3n*x^3*y^2n*y^4的值如题..
x=5,y=-1/5,n为自然数,求x^3n*x^3*y^2n*y^4的值
如题..

x=5,y=-1/5,n为自然数,求x^3n*x^3*y^2n*y^4的值如题..
x^3n*x^3*y^2n*y^4
=x^(3n+3)*y^(2n+4)
=(x^3)^(n+1)*y^(2n+2)*y^2
=(x^3)^(n+1)*(y^2)^(n+1)*y^2
=(x^3*y^2)^(n+1)*y^2
=(125*1/25)^(n+1)*(1/25)
=5^(n+1)*1/25
=5^n*5*1/25
=(5^n)/5

x^(3n)*x^3*y^(2n)*y^4
=x^[3(n+1)]*y^(2n+2)*y^2
=(x^3)^(n+1)*(y^2)^(n+1)*y^2
=(x^3*y^2)^(n+1)*y^2
=[(xy)^2*x]^(n+1)*y^2
=5^(n+1)*(-1/5)^2
=5^(n+1)*5^(-2)
=5^(n-1).

x^3n*x^3*y^2n*y^4=x^(3n+3)*y^(2n+4)=5^(3n+3)*(-5)^(-(2n+4))
=5^(3n+3)*5^(-(2n+4))=5^(3n+3-2n-4))=5^(n-1)

(x^3n)(x^3)(y^2n)(y^4)
=[x^(3n+3)][y^(2n+4)]
1.如果3n+3=2n+4,(n=1)
原式=1
2.如果3n+3>2n+4,(n>1）
原式=x^(3n+3-2n-4)=x^(n-1)
3.如果3n+3<2n+4,(n<1)
原式=y^(2n+4-3n-3)=y^(1-n)
经验证，楼上几位答案正确。