Help for Question 7 on your Module 4 Lesson 2 Assignment.

1. SOLVING A LOGARITHMIC
EQUATION

2. SOLVETHE EQUATION BELOW FOR E IFYOU
KNOWTHATTHE MAGNITUDE (R) IS 8.7
𝑅 = −3 + 0.5 LN 𝐸
Plug in 8.7 for R
8.7 = −3 + 0.5 ln 𝐸
Next, add three to both sides to get the equation:
11.7 = 0.5 ln 𝐸

3. 11.7 = 0.5 LN 𝐸
Divide both sides by 0.5 to get the natural log (ln)
alone.
11.7
0.5
= ln 𝐸

4. 11.7
0.5
= LN 𝐸
To get E alone, change the equation to
exponential form. Remember, since there
is no base written, it has an understood
base of e (2.718…).
𝑒
11.7
0.5 = 𝐸

5. 𝑒
11.7
0.5 = 𝐸
 Evaluate this on your calculator. Remember, the e button is
found by pushing 2nd divide.
 You get the answer: 1.4538 𝑥 1010
 Remember, the numbers may seem off because this is just an
example problem. Use the correct values associated with your
assignment.