對(duì)數(shù)與對(duì)數(shù)的運(yùn)算練習(xí)題及答案

1、對(duì)數(shù)與對(duì)數(shù)運(yùn)算練習(xí)題及答案選擇題1 . 2-3=1化為對(duì)數(shù)式為()8可編輯A. log -2 = 38iB. log -(-3) = 281C. log 21一31D. log 2(-3) = -82. log 63 +log 62 等于()A. 6B. 5C. 1D . log 653.如果 lgx= lg a+21gb 3lg c,貝U x 等于()B. a+b2c3ab22abD.3c4.已知 a=log 32 ,那么 log 38-2log 36 用 a 表示為()B. 5a 2C. 3a (1 +a)221 + 士-的值等于(A. 2 + /55C. 2十 ° 26. Lo

2、g2、/2的值為()A. - /B.D.D . 3a- a2- 1C.1DI27 .在b = log (a-2)(5 a)中，實(shí)數(shù)a的取值范圍是()A. a>5 或 a<2B. 2<a<3 或 3vav 5C. 2< a<5D. 3vav48 .方程210g3x=的解是（）41A. x=一9C. x="J3B.D.x= 99.若 log 2(1og 3x)= log 3(1og 4y) = log 4(1og 2z) = 0,則 x+y+z 的值為(A.B.C.D.10 .若 102x=25,則 x 等于(1A. lg 一 5B. 1g5C.21g

3、51D. 2lg -11 .計(jì)算log 89 - 10932的結(jié)果為（A. 4513B-C-D-345)12 .已知 log ax= 2 , log bx= 1 , log cx= 4(a, b , c, x>0 且w1)則 log x(abc)=(4A72B-77C- 27D-4二.填空題1 . 2log 510 +log 5 0.25 =.2 .方程 log 3(2x- 1) = 1 的解為 x=.3 .若 lg(ln x)=0,貝U x=.4 .方程9x- 6 x3-7=0的解是5 .若 log 34 - lo48 - 108m = log 416 ,則 m =.6 .已知 log

4、 a2 = m , log a3 = n ,則 log a18 =H m , n 表示)7 . log 6log 4(log 381) =.8 .使對(duì)數(shù)式10g(x-i)(3 x)有意義的x的取值范圍是 三.計(jì)算題1 .計(jì)算：1g3 + 21g2 1(2)1g1.2210g 2 10 + log 20.0410g 621og 63 + -log 627123(4)1og 2(3 + 2) + log 2(2/);2 .已知 log 34 - 1048 - 10gm = log 416 ,求 m 的值.對(duì)數(shù)與對(duì)數(shù)運(yùn)算練習(xí)題答案一.選擇題1. C 2. C 3. C 4. A 5. B 6. D

5、7. B 8 A 9. A10.B11.B12.D二.填空題1.22.23. e 4. x=log 375.96. m+2n 7.08. 1< x<3 且 x2三.計(jì)算題1.解:(1)2log 210 +log 20.04 = log 2(100 X 0.04) log24 = 2lg3 + 2lg2 1(2)')lg1.2lg(3X 4 + )0 lg1.2 =1lg1.2lg1.21(3)log 6 -2log163 + -log 627 = log 63 、112 一 log 69 + log 63=log 6(X-X 3)擔(dān)g 6 =-2. 12 936(4)log 2(/3 +2) + log 2(23)=log 2(2 +