SOLUTION: log_4(7x)=3

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Question 1204930: log_4(7x)=3
Found 2 solutions by MathLover1, ikleyn:
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

log%284%2C%287x%29%29=3....change to base 10
log%28%287x%29%29%2Flog%284%29=3
log%28%287x%29%29=3log%284%29
log%28%287x%29%29=log%284%5E3%29
7x=4%5E3
x=64%2F7


Answer by ikleyn(52803) About Me  (Show Source):
You can put this solution on YOUR website!
.

They want you solve equation 

    log%284%2C%287x%29%29 = 3.


From this equation,

    7x = 4%5E3 = 4*4*4 = 64,

     x = 64%2F7.   


ANSWER.  x = 64%2F7.

Solved.

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To solve this problem, there is NO any need to change the base, as @MathLover1 does.

Is is an excessive operation, which actually is not needed.

Solving problems with excessive operations is NOT a good decoration. In opposite, it is a bad style.