Page 23 of 45
Print | Beginning & Intermediate Algebra
1/31/2014
...

PRINTED BY: [email protected] Printing is for personal, private use only. No part of this book may be reproduced or transmitted without publisher's prior permission. Violators will be prosecuted.
Student Practice 9
Evaluate.
(a)
log
7
1
(b)
log
8
8
(c)
Find
y
if log
12
13 = log
12
(
y
+ 2).
We now have the mathematical tools needed to solve a variety of logarithmic equations.
EXAMPLE 10
Find
x
if 2 log
7
3
−
4 log
7
2 = log
7
x
.
Solution
We can use property 3 in two cases.
By substituting these results, we have the following.
log
7
9
−
log
7
16 = log
7
x
Student Practice 10
Find
x
if log
3
2
−
log
3
5 = log
3
6 + log
3
x
.
744745
12.3 Exercises
Express as a sum of logarithms.
1.
log
3
AB
2.
log
12
CD
3.
log
5
(7
· 11)
4.
log
6
(13 · 5)
5.
log
b
9
f
6.
log
b
5
d
Express as a difference of logarithms.
7.
8.
9.
10.
11.
12.
Express as a product.
13.
log
8
a
7
14.
log
3
c
8
15.
log
b
A
−
2
16.
log
a
B
−
5
17.
Page 24 of 45
Print | Beginning & Intermediate Algebra
1/31/2014
...

PRINTED BY: [email protected] Printing is for personal, private use only. No part of this book may be reproduced or transmitted without publisher's prior permission. Violators will be prosecuted.
18.
Mixed Practice
Write each expression as a sum or difference of logarithms of a single variable.
19.
log
8
x
2
y
20.
log
6
xy
4
21.
22.
23.
24.
25.
26.
Write as a single logarithm.
27.
log
4
13 + log
4
y
+ log
4
3
28.
log
8
15 + log
8
a
+ log
8
b
29.
5 log
3
x
−
log
3
7
30.
3 log
8
5
−
log
8
z
31.
32.
745746
Use the properties of logarithms to simplify each of the following.
33.
log
3
3
34.
log
7
7
35.
log
e
e
36.
log
10
10
37.
log
9
1
38.
log
e
1
39.
3 log
7
7 + 4 log
7
1
40.
Find x in each of the following.
Page 25 of 45
Print | Beginning & Intermediate Algebra
1/31/2014
...