Name Date
WORKSHEET 8.20: SOLVING LOGARITHMIC EQUATIONS
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A logarithmic equation is an equation that contains a logarithmic expression. Solve
logarithmic equations by following the steps below:
- Rewrite the equation in exponential form.
- Solve the exponential equation.
EXAMPLES
log 2 x=5logx 216 =3log 381 =x
25 =xx^3 = 216 3 x=81; 81= 34
32 =xx= 216
1
(^3) orx= 63 x= 34 orx= 4
DIRECTIONS: Solve.
- log 42 =x 2. log 5125 =x
- log 82 =x 4. logx
1
7
=− 1
- log 25 x=
1
2
- log 6
1
36
=x
- log 864 =x 8. log 16 x=−
1
2
- logx 243 = 5 10. log 264 =x
CHALLENGE:Elena solved log 10010 =xand found thatx=2because
102 =100. Is she correct? Explain your reasoning.
313
Copyright
©
2011 by Judith A. Muschla, Gary Robert Muschla, and Erin Muschla. All rights reserved.