SOLUTION: I need help with the following exponential please. Solve: 7^-x-3* 7^1+x -4=0 Please note that -4 is not part of 7^1+x Thank you very much. I have a test in the morning and

Question 294874: I need help with the following exponential please.
Solve: 7^-x-3* 7^1+x -4=0
Please note that -4 is not part of 7^1+x
Thank you very much. I have a test in the morning and I really want to make sure I have these questions right.

Answer by Fombitz(32388) (Show Source): You can put this solution on YOUR website!
Ugh. Please use more parentheses, they're free and help avoid confusion.
I think this is what you want. If not please re-post.

Clearly this is not true. There is no solution.
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<<----- ADDITIONAL INFORMATION ----->>
>> This is what I mean. <<
OK, that's clearer.

Again, multiply by .

Pull out a 7 from the second term.

Re-arrange.

Substitute, let , then

This quadratic is factorable.

Two solutions using the zero product rule:

Now substitute back

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No solution here, since log requires positive arguments.
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Verify the one solution.

Good solution.

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