——-　——　　———　an hour_____ ______to the zoo

数列An+An+1—1=n(An+1-An-1),求An的通项公式.用逐差法. 【 】Lily has —uncle and —aunt.A,a;a B,an;an C,an;a D,a;an 等差数列{An}中,An不等于0,An-1—An^2—An+1=0,S2n-1=38.则n等于?A10 B19 C20 D38 等差数列An中,An不等于0,An+1—An的平方+An-1=0（n≥2）,若S2n-1=38,则n=? 英语翻译——　an　umbrella． 托福考前DA/AN——925199780 一道数学题目 要说明过程哦!数列{an}中,an>0,且{（an）*（an+1）}是公比为q(q>0)的等比数列,满足(an)*(an+1)+(an+1)*(an+2)>(an+2)*(an+3) (n属于自然数）,则公比q的取值范围是——（题中n n+1等 均为下标 This book is （——）orange.It‘s（——）orange book.有四个选项,分别是/ ,a /,an a,a an,an有四个选项,分别是A:/,a B:/,an C:a,a D:an,an 对 感兴趣 英文 —an interest in this is ——usual shirt ,but this is—— unusual shirt A an ,a B a,a C an,an D a,an 已知数列{an} 满足a1=1/5,且当n>1,n∈N+时,an—1/an=2an—1+1/1—2an(1)求证：数列{1/an} 为等差数列； Do you want an apple?同义句—— —— —— an apple?快 would you like an apple (同义句)—— —— ——an apple? 在数列{an}中.a1-1且an—an-’-巾-i-n(nEN’．n≥2),求an.由已知得：an=(an—aM)+(a¨一an_2)+⋯+(a2一a1)+a1为什么啊 在数列an中a1=—20,an+1+an=3n-54,求通项公式 数列｛an｝满足a1=2,且3an+1—an=0,则a4是多少? —Is this _________ interesting book?—Yes,this book is _______ interesting.A.an,an B./,/ C.an,/ D./,an —Is this ___ English car — No,it’s ___ Japanese car.A.a; a B.a; an C.an; an D.an; a