2^n+2^n-3*2^(n+1)
=(2^n+2^n)-3*2^(n+1)
=2*2^n-3*2^(n+1)
=2^(n+1)-3*2^(n+1)
=-2*2^(n+1)
=-2^(n+2)
好久沒做也花了點(diǎn)時(shí)間 如果還有哪些不懂可以問我太感謝你了??！謝謝??！~~~如果不麻煩的話——我想再問一道：x的3n+1次冪乘以x加3x的n+1次冪乘以x的2n+1次冪 嘻嘻~~ 還有這道不會(huì)??！~~X^(3n+1)*x+3x^(n+1)*x^(2n+1)=X^(3n+2)+x^3(n+1)*x^(2n+1)=X^(3n+2)+x^(3n+3+2n+1)=x^(3n+2)+x^(5n+4)憑我的印象是怎么做的不知道對(duì)不對(duì)那個(gè)~~~我想問一下你確定你做對(duì)了嗎？？O(∩_∩)O哈哈~錯(cuò)了，重新看了遍，我去問問其他人好久沒做了。。。。那你還是好好看看吧，這是很重要的作業(yè)！！慎重慎重啊?。?！最好兩道題都看看?。∵€有你多大了？？第一題絕對(duì)是對(duì)的，但第二題忘記怎么做了，我初二據(jù)我所知第二道題的答案是4x的6n+4次冪，第一道是4n-6的n+1次冪 唉~你再好好看看吧??！你可一定要想出來啊?。÷闊┠惆。“萃衺~~~第二題我算出來是X^(3n+1)*x+3x^(n+1)*x^(2n+1)=X^(3n+2)+3*x^(n+1)*x^(2n+1）=X^(3n+2)+3*x(n+1+2n+1)=X^(3n+2)+3X^(3n+2)=4x^(3n+2)等你明天的答案