stuck with this one solve for x: 16^x-5*8^x=0
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Originally Posted by calmo11 stuck with this one solve for x: 16^x-5*8^x=0 $16^x-5*8^x=0$ $16^x = 5*8^x$ take logs base 2 $4x=3x+\log_2(5)$ $x = \log_2(5)$
Or for log to any base, x log(16)= log(5)+ x log(8) so x(log(16)- log(8))= x(log(16/8))= x(log(2))= log(5) and x= log(5)/log(2). Another way to do this is, since [tex]8^x[/itex] is never 0, to divide both sides by : and then so
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