SOLUTION: How do you solve 12^2x-8=15

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Question 973207: How do you solve 12^2x-8=15
Found 2 solutions by Alan3354, MathLover1:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
What is the exponent of 12?
2x ?
2x-8 ?
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Parentheses are free.

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
if you have
12%5E%282x%29-8=15 then
12%5E%282x%29=15%2B8....use log base ten
log%2812%5E%282x%29%29=log%2823%29
%282x%29log%2812%29=log%2823%29
2x=log%2823%29%2Flog%2812%29
x=%28log%2823%29%2Flog%2812%29%29%2F2
x=%28log%2823%29%2F2log%2812%29%29
x=%28log%2823%29%2F2log%282%5E2%2A3%29%29
x=x+=+log%2823%29%2F%282%282log%282%29%2Blog%283%29%29%29
x=0.6309 => approximately

but, if you have
12%5E%282x-8%29=15 then
log%2812%5E%282x-8%29%29=log%2815%29
%282x-8%29log%2812%29=log%2815%29
2x-8=log%2815%29%2Flog%2812%29
2x-8=log%283%2A5%29%2Flog%283%2A2%5E2%29
2x-8=%28log%283%29%2Blog%285%29%29%2F%28log%283%29%2B2log2%29%29
2x=%28log%283%29%2Blog%285%29%29%2F%28log%283%29%2B2log2%29%29%2B8
x=%28log%283%29%2Blog%285%29%29%2F%28log%283%29%2B2log2%29%29%2F2%2B8%2F2
x=%28log%283%29%2Blog%285%29%29%2F%282%28log%283%29%2B2log2%29%29%29%2B4
approximately x=4.5449