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March 5, 2015

March 5, 2015

Posted by **bob** on Friday, January 23, 2009 at 3:04pm.

4^-x=8?

a. log8 4=x

b. logx = -4

c. log -x 4=8

d. log 4 8= -x

- math -
**Damon**, Friday, January 23, 2009 at 4:30pm1/4^x = 8

4^x = 1/8

x log4 (4) = log4 (1/8)

but log4 (4) = 1 because b^logb(a) = a

x = log4(1/8) = log4(1) - log4(8)

but log4(1) = 0 for the same reason

so

x = -log4(8) or -x = log4 (8)

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