Date: 5 May 1995 14:00:34 -0400 From: Harvey Robicheau Subject: Home work with logs Solve: 3(3^x)+9(3^-x) = 28 Harvey J. Robicheau firstname.lastname@example.org soccer coach Naches Valley High School Box 463 Naches,Washington 98937
Date: 5 May 1995 14:30:28 -0400 From: Dr. Ken Subject: Re: Home work with logs Hello there! The first thing I think I'd do is lump the 3 and the 9 into the exponential terms like this: 3(3^x)+9(3^-x) = 3^(x+1) + 3^(2-x) = 28 Now, to be honest, I think the easiest way to proceed from here is just by inspection. Can you come up with two powers of 3 that add up to 28? If you can, then see if you can get x-1 to be one power and 2-x to be the other. If you're still stuck, don't hesitate to write us back. Thanks! -K
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