已知x^2n=3,求(3x^3n)^2的值 大侠们

问题描述:

已知x^2n=3,求(3x^3n)^2的值 大侠们
随便把这个题也解了 若x=-5,y=1/5,求x^2及x^2n(y^n+1)^2的值

(3x^3n)^2
=9x^6n
=9(x^2n)^3
=9*3^3
=9*27
=243
x^2
=(-5)^2
=25
x^2n(y^n+1)^2
=x^2n*(y^n*y)^2
=x^2n*y^2n*y^2
=(x*y)^2n*y^2
=(-5*1/5)^2n*(1/5)^2
=(-1)^2n*1/25
=1/25