To solve an exponential equation, take the log of both sides, and
solve for the variable.
Problem 4: Solve for x in the equation
Solution:
Note that it crosses the x-axis only once between 6 and 7. This means there is just one real solution and that solution is between 6 and 7.
to get
is the exact answer and
is the approximate answer.
Check: Let's check the approximate answer with the original problem. When we substitute the above value of x in the left side of the equation, we get
You can also check your answer by graphing the function
and note where it crosses the x-axis. If you have worked the problem
correctly, it should be the same values of x.
If you would like to review another example, click on Next Problem.
Do you need more help? Please post your question on our S.O.S. Mathematics CyberBoard.
Author: Nancy Marcus