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by **baronthered** on Mon Apr 06, 2009 11:02 pm

I'm having trouble remembering how to solve for the variable in the fractional exponent. An example would be (844)3^t/4=22788. I know both sides divided by 844 gives 27=3^t/4 or 3³=3^t/4 I'm trying to solve for t (Growth over time problem). Thanks in advance.

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by **stapel_eliz** on Mon Apr 06, 2009 11:16 pm

baronthered wrote:...(844)3^t/4=22788. I know both sides divided by 844 gives 27=3^t/4 or 3³=3^t/4 I'm trying to solve for t (Growth over time problem).

You've already done the hard part! :wink:

For this sort of exponential equation, once you've got an equation with the same base on either side of the "equals" sign, just equate the powers, and solve the resulting equation. For instance:

. . . . . $8^{3x+2}\, =\, 16^{5-x}$

. . . . . $(2^3)^{3x+2}\, =\, (2^4)^{5-x}$

. . . . . $2^{3(3x+2)}\, =\, 2^{4(5-x)}$

. . . . . $3(3x\, +\, 2)\, =\, 4(5\, -\, x)$

...and so forth.

by **baronthered** on Mon Apr 06, 2009 11:40 pm

the t/4 should read as t divided by 4. I'm trying to isolate t I'm thinking I need to multiply both sides of the exponents by 4 to even things up. I never can remember the exact rules for this. :oops:

by **stapel_eliz** on Tue Apr 07, 2009 2:11 am

Is my previous reply not displaying for you? (I'd explained the process, provided a link to a lesson with an explanations and many worked examples, and provided a similar example, but you don't seem aware of the contents...?)

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Fractional exponents with a variable: (844)3^(t/4)=22788

Fractional exponents with a variable: (844)3^(t/4)=22788

Re: Fractional exponents with a variable: (844)3^(t/4)=22788