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        riddles >> medium >> Math problem that came to me in a dream
        
(Message started by: marsh8472 on Jun 4^th, 2014, 9:30pm)

Title: Math problem that came to me in a dream
Post by marsh8472 on Jun 4^th, 2014, 9:30pm

I was dreaming about a math class I was in. The professor gave us this problem:

3^2.5x + 3^3.3x = 18

Traditional log rules don't seem to apply to simply this.

I know the answer is about 0.67600464 but how would you go about finding the precise answer?

Title: Re: Math problem that came to me in a dream
Post by towr on Jun 4^th, 2014, 10:39pm

I don't think there is a precise answer using simple function/operators.

Title: Re: Math problem that came to me in a dream
Post by dudiobugtron on Jun 5^th, 2014, 2:56pm

I think if there were a simple way of manipulating A^x + B^x = C, people would have solved Fermat's last theorem a lot sooner! :)

Title: Re: Math problem that came to me in a dream
Post by BMAD on Jun 5^th, 2014, 7:25pm

Not sure of this is what you mean but:

3^2.5x + 3^3.3x =18
U = 3^2.5
(3^(2.5))^x) + (3^(2.5)^1.32x) =18
U^x + U^1.32x = 18
R = U^x
R + R^1.32 = 18
R = 6.4023655 (aprox)
U^x = 6.4023655
(3^2.5)^x = 6.4023655
3^2.5x=6.4023655
X = .676