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#1

$Old$ April 21st, 2009, 09:30 PM

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$Exclamation$ Solving an exponential equation question 2

solve the exponential function:

4(2^x) + 31(2^x) - 8 = 0

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$Old$ April 21st, 2009, 09:33 PM

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Originally Posted by math123456 $View Post$

solve the exponential function:

4(2^x) + 31(2^x) - 8 = 0

It simplifies to $2^x = \frac{8}{35}$ . Solve this.

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#3

$Old$ April 22nd, 2009, 12:23 AM

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$Exclamation$ Solving an exponential equation question 2

How do you solve for x:

2^x = 8/35

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$Old$ April 22nd, 2009, 12:32 AM

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Originally Posted by math123456 $View Post$

solve for x:

2^x = 8/35

Take logs:

$x \log(2)=\log(8/35)$

and solve.

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$Old$ April 22nd, 2009, 01:49 PM

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how would you answer that in exact form

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$Old$ April 22nd, 2009, 02:03 PM

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Originally Posted by CaptainBlack $View Post$

Take logs:

$x \log(2)=\log(8/35)$

and solve.

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Quote:

Originally Posted by math123456 $View Post$

how would you answer that in exact form

Divide through by log(2) to isolate it. The exact form will have log terms in it:

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