5 to the power of x subtract 5 to the power of negative x over 5 to the power of x plus 5 to the power of negative x all equals 8. Can anyone help me get started on this problem or help me work through it.

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- Jul 22nd 2008, 12:12 AMhelpless13I'm Lost
5 to the power of x subtract 5 to the power of negative x over 5 to the power of x plus 5 to the power of negative x all equals 8. Can anyone help me get started on this problem or help me work through it.

- Jul 22nd 2008, 08:19 AMtutor
(5^x-5^-x)/( 5^x+5^-x)=8

(5^2x-1)/(5^2x+1)=8

Let 5^x = P

P^2-1/P^2+1=8

8P^2+8=P^2-1

7P^2=-9

P^2=-9/7

P=+ or - 3i/sqrt7

we consider p=5^x

hence 5^x=-3i/sqrt7

still if u need to calculate x value make an apply log on both sides.