若n为正整数,且x的2n次方=7,求7(x的3n次方)的3次方—3(x的2次方)的2n次方的值 急啊。谢谢了

2025-02-27 23:32:58
推荐回答(1个)
回答1:

x^(2n)=7
7(x^(3n))^2-3(x^2)^(2n)
=7(x^(6n))-3(x^(4n))
=7((x^(2n))^3)-3((x^(2n))^2)
=7(7^3)-3(7^2)
=2254