SOLUTION: Solve logarithmic equation: 12^(4-x)=20

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Question 867033: Solve logarithmic equation: 12^(4-x)=20
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
12%5E%284-x%29=20


log%28%2812%5E%284-x%29%29%29=log%28%2820%29%29 Apply logs to both sides.


%284-x%29%2Alog%28%2812%29%29=log%28%2820%29%29 Pull down the exponents.


4-x=log%28%2820%29%29%2Flog%28%2812%29%29


4=log%28%2820%29%29%2Flog%28%2812%29%29%2Bx


4-log%28%2820%29%29%2Flog%28%2812%29%29=x


x+=+4-log%28%2820%29%29%2Flog%28%2812%29%29


x+=+4-log%2812%2C%2820%29%29 Use the change of base formula