Solve 3^(x – 4) = 7^(x + 9)

- anonymous

Solve 3^(x – 4) = 7^(x + 9)

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- chestercat

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- anonymous

what to do wuth this question?
Which Chapter Question??

- anonymous

i am in florida virtualll....

- anonymous

name the chapter or topic of your book from which this question u have asked!!

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## More answers

- anonymous

OK, so you're having trouble with the same stuff.
1) please don't keep repeat-posting your questions. That's against our Code of Conduct
2) What specifically are you having trouble with. The entire theory?

- anonymous

sorry laura. Where can i check the code of cunduct so i dont make that mistake?

- anonymous

- anonymous

ok thank you . And are you like in charge of the program?

- anonymous

I'm one of the staff members here on site, yes.

- anonymous

ohh. And you asked me what i was having trouble with... mostly with the entriel theory of logs actuall :S

- anonymous

do you think you can help me with logs?

- anonymous

No, I really can't help with logs. Sorry. I don't remember most of this math....

- anonymous

ohhh, do who know any group member that can help me with this?

- ash2326

@sofia I'd help you. Do you need an explanation on logarithms?

- Shayaan_Mustafa

@sofia_smr
What help you want with logs?

- bahrom7893

Take LN on both sides:
Ln(3^(x-4))=Ln(7^(x+9))
Using the property Lna^b=b*Lna:
(x-4)Ln3=(x+9)Ln7

- anonymous

Input Interpretation: solve ; 3 ^ x-4 = 7 ^ x+9
Results: this soo hard to type because of lag and error equation so i post a site
that just show you the answer and hopefully you know how to do the equation
http://www.wolframalpha.com/bing/?i=solve+3%5e(x+-+4)+%3d+7%5e(x+%2b+9)&expl=3

- anonymous

i cant understand pretty much everything about them :S

- anonymous

it shows results, real solution and plot.

- bahrom7893

Distribute and simplify.. i gotta go to class bbl

- Shayaan_Mustafa

3^(x-4)=7^(x+9)
Take the natural logarithm of both sides of the equation to remove the variable from the exponent.
ln(3^(x-4))=ln(7^(x+9))
The left-hand side of the equation is equal to the exponent of the logarithm argument because the base of the logarithm equals the base of the argument.
xln(3)-4ln(3)=ln(7^(x+9))
The exponent of a factor inside a logarithm can be expanded to the front of the expression using the third law of logarithms. The third law of logarithms states that the logarithm of a power of x is equal to the exponent of that power times the logarithm of x (e.g. log^b(x^(n))=nlog^b(x)).
xln(3)-4ln(3)=((x+9)ln(7))
Multiply ln(7) by each term inside the parentheses.
xln(3)-4ln(3)=(xln(7)+9ln(7))
Since xln(7) contains the variable to solve for, move it to the left-hand side of the equation by subtracting xln(7) from both sides.
xln(3)-4ln(3)-xln(7)=9ln(7)
Factor out the GCF of x from each term in the polynomial.
x(ln(3))+x(-ln(7))=4ln(3)+9ln(7)
Factor out the GCF of x from xln(3)-xln(7).
x(ln(3)-ln(7))=4ln(3)+9ln(7)
Divide each term in the equation by (ln(3)-ln(7)).
(x(ln(3)-ln(7)))/(ln(3)-ln(7))=(4ln(3))/(ln(3)-ln(7))+(9ln(7))/(ln(3)-ln(7))
Simplify the left-hand side of the equation by canceling the common factors.
x=(4ln(3))/(ln(3)-ln(7))+(9ln(7))/(ln(3)-ln(7))
Simplify the right-hand side of the equation by simplifying each term.
x=(4ln(3)+9ln(7))/(ln(3)-ln(7))

- anonymous

ok thanks a lot though, good luck

- anonymous

(x-4)log3 = (x+9)log7
Sofia, sorry i don't gotta calculator :/

- ash2326

@sofia_smr Did you understand?

- anonymous

yes! shaayaan gave me a great example there!

- Shayaan_Mustafa

Thanks.

- anonymous

glad you got help by someone :)

- anonymous

thanks guys!

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