题目

已知为等比数列前项和，，，则        . 答案：解析:结合题意考虑利用等比数列前项和的性质求解.是等比数列，为等比数列， . 【名师指引】给项求项问题，先考虑利用等比数列的性质，再考虑基本量法. 书面表达 请你以“My flat”为题，写至少6句话，描述你的公寓。下面问题可供你参考。 1．Where do you live? 2．What kind of flat do you live in? 3．How many rooms are there in your flat? What are they? 4．How much does your flat cost? 5．How big is your flat? 6．Do you like to live in your flat? Why? __________________________________________________ __________________________________________________