SOLUTION: Solve: (2^x)-(3^x)=0 I tried to bring it to base 2 but it didn't work. Please show us steps. Thank you.

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: Solve: (2^x)-(3^x)=0 I tried to bring it to base 2 but it didn't work. Please show us steps. Thank you.       Log On


   



Question 74624This question is from textbook Algebra and Trignometry
: Solve:
(2^x)-(3^x)=0
I tried to bring it to base 2 but it didn't work. Please show us steps.
Thank you.
This question is from textbook Algebra and Trignometry

Answer by Edwin McCravy(20086) About Me  (Show Source):
You can put this solution on YOUR website!

: Solve: 
(2^x)-(3^x)=0 
I tried to bring it to base 2 but it didn't work. Please show us steps. 
Thank you. 

2x - 3x = 0

     2x = 3x

There are two log bases on your
calculator, "log" which is the 
logarithm base 10, and "ln" which
is the natural logarithm base "e".
You can use either one:

If we use "log", we take the log     |    If we use "ln", we take the ln
of both sides:                       |    of both sides:

  log(2x) = log(3x)                          ln(2x) = ln(3x)
                                     |
Now we use the rule of logs to       |    Now we use the rule of lns to
rewrite both sides:                  |   rewrite both sides:
                                     |
  log(AB) = B·log(A)                        ln(AB) = B·ln(A)
                                     |
 x·log(2) = x·log(3)                 |     x·ln(2) = x·ln(3)
                                     |
Get 0 on the right                   |   Get 0 on the right
                                     |
 x·log(2) - x·log(3) = 0             |    x·ln(2) - x·ln(3) = 0
                                     |
Factor out x on the left:            |   Factor out x on the left:     
                                     |
 x·[log(2) - log(3)] = 0             |    x·[ln(2) - ln(3)] = 0
                                     |
Using the calculator:                |   Using the calculator:
                                     |
     x·{.301 - .477) = 0             |    x·(.693 - 1.099) = 0
                                     |
           x·(-.176) = 0             |           x·(-.406) = 0
                                     |
              -.176x = 0             |              -.406x = 0
                                     |
Divide both sides by -.176           |  Divide both sides by -.406
                                     |
                   x = 0             |                   x = 0
                                     |
                    Either way you get x = 0 

Checking:
             2x - 3x = 0
             20 - 30 = 0
               1 - 1 = 0
                   0 = 0

Edwin