[r]
Trang 1A.Mét sè bµi to¸n c¬ b¶n:
1).Gi¶i c¸c ph¬ng tr×nh :
a)
2
2 4x x 256 b) 2 5x x 0 01, c) 2x 3x 216 d)
2 1
4 9 3 2
x
2).Gi¶i c¸c bÊt ph¬ng tr×nh
a) 3x+2 < 9 b)
2 2
2 8 20
1
8 2
x x
3) Gi¶i c¸c ph¬ng tr×nh :
a) 4x + 2x+1 - 3 = 0 b) 4x +5x = 9x
c) 3x = 11- x d) 4.9x +12x -3.16x = 0
e) 9x +2(x-2).3x +2x -5 = 0
4) Gi¶i c¸c ph¬ng tr×nh :
c) -log3x +2log2x = 2- logx d) logx +logx2 = log9x
e) log(x2-x-6)+x = log(x+2) +4 e) log(1+ x) = log
3x
B.Mét sè bµi thi tõ n¨m 2002-2008
I.Gi¶i ph ¬ng tr×nh mò vµ logarit
1).23x+1 -7.22x +7.2x -2 = 0 2)3.8x +4.12x -18x -2.27x = 0
3)9x
2
+x− 1 −10 3 x2
+x −2
2x x 4.2x x 2 x 4 0
5)log3(x-1)2 +log (23 x 1)
= 2 6)logx2 +2log2x4 = log 2x8
7)log√2√x +1 − log1
2
(3 − x)− log8¿
8)log2(4x+15.2x +27 ) + 2
1
4.2x 3
9)log4 (x-1) +
1 log2 x+14=
1
2+log2√x+ 2
4
1
1 log x
11)log3(3x-1)log3(3x+1-3) = 6 12)
log x (2x x 1) log (2 x x1) 4
13)log2(4x+15.2x +27 ) + 2
1
4.2x 3
1
4 = 0.
15)
log x (2x x 1) log (2 x x1) 4
16).3x- log68x = log6(33x + x2 – 9) 17)log2x + 2log7x = 2 + log2xlog7x 18)logx2(2 + x) + log❑√2+xx = 2
II.Gi¶i bÊt ph ¬ng tr×nh vµ logarit
1)
2 0,7 6
4
x
2 1 2
0
x
3)(logx8+log4x2)log2 2x 0 4)log1
2
√2 x2− 3 x +1+1
2log2( x − 1)2≥1
2 5)logx+1(-2x) > 2 6)log5(4x +144) -4log52 < 1 + log5(2x-2 + 1)
7) log3
¿ ¿
2 1 2
0
x
9)
3
2log (4x 3) log (2 x3) 2
10)(x + 1)
log1 2
2
x + ( 2x + 5)
log1
2x + 6 0
11)
2 1
3 1
3 3
2 2 3
1
3
log log x log x
2 0,7 6
4
x
13)2log3(x – 2) + log3(x – 4)2 = 0 14)log22
x+(x − 1)log2 x=6 −2 x 15) 1+log6 x −1
x+ 7=
1
2log6¿16)log4¿ 17)logx −1(x2− x)> 2. 18) log2x + log3x <
1 Giải phương trình :
2
log x log 9 x 9
3 3 10
Trang 23 Giải phương trình: a
2
log x 6log x 4 b 4 2.2 1 3 0
1
x
1
2
1
x
x
4 2 3 0.
6 2 3
x
13 Giải phương trình :
1
2 1
3 9.3 6 0
.
16 Giải phương trình log (3 x 2) log ( 3 x 2) log 5 3 17 Giải bất phương trình
1
( 2 1) ( 2 1)
x
)
log x log 4 x 5