SOLUTION: what is log4 to base2 with the addition of log7 to base2 then subtract logX to base 2=1

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Question 260775: what is log4 to base2 with the addition of log7 to base2 then subtract logX to base 2=1
Answer by drk(1908) About Me  (Show Source):
You can put this solution on YOUR website!
We have
log%282%2C4%29+%2B+log%282%2C7%29+-+log%282%2Cx%29+=+1
by rules of logs we get
log%282%2C28%2Fx%29+=+1
rewriting as powers, we get
2%5E1+=+28%2Fx
so,
x = 14.