论文部分内容阅读
一、选择题（本题满分36分,每小题6分）1.若 a>1,b>1,且lg（a+b）= lga+lgb, 则 lg（a- 1）+lg（b-1）的值 （） （A）等于lg2（B）等于1 （C）等于0 （D）不是与a,b无关的常数2.若非空集合 A=|x|2a+1≤x≤3a-5, B=|x|3≤x≤22,则能使A（?）A∩B成 立的所有a的集合是 （） （A）|a|1≤a≤9} （B）|a|6≤a≤9 （C）|a|a≤9} （D）￠3.各项均为实数的等比数列|a_n|前n项之 和记为S_n,若S_(10)=10, S_(30)=70,则 S_(40)等 于 （）
First, multiple-choice questions (out of 36 points for this question, 6 points for each question) 1. If a> 1, b> 1, and lg (a + b) = lga + lgb, then lg (a - 1) + lg (b The value of -1) () (A) is equal to lg2 (B) is equal to 1 (C) is equal to 0 (D) is not constant independent of a, b 2. If non-empty set A=|x|2a+1≤x≤3a -5, B=|x|3≤x≤22, then the set of all a that make A(?)A?B true is () (A)|a|1≤a≤9} (B)|a |6≤a≤9 (C)|a|a≤9} (D) ¢ 3. The geometrical series with all real numbers |a_n | The sum of the preceding n entries is denoted as S_n, if S_(10) = 10 S_(30)=70, then S_(40) is equal to ()