若n为正整数,且x的3n次方=7,则2[x的2n次方*4的n次方(-x)的2n次方]的立方/(-2x)的6n次方=?
问题描述:
若n为正整数,且x的3n次方=7,则2[x的2n次方*4的n次方(-x)的2n次方]的立方/(-2x)的6n次方=?
答
若n为正整数,且x的3n次方=7,
则2[x的2n次方*4的n次方(-x)的2n次方]的立方/(-2x)的6n次方
=2[x^2n* 2^2n*x^2n]的立方/(2^6x^6n)
=2[2^2n*x^4n]的立方/(2^6nx^6n)
=2[2^6n*x^12n]/(2^6nx^6n)
=2*x^6n
=2*(x^3n)^2
=2*7^2
=98