5^-x = 1/125
i know the anser is, x=3, but i need to show working out :S
algebra help, simple exponential equations?
2009-08-12 10:16 am
回答 (4)
2009-08-12 10:31 am
✔ 最佳答案
5^-x = 1/1255^(-x)=5^-3
-x=-3
x=3 answer//
2009-08-12 5:37 pm
5^-x = 1/125
1/(5^x) = 1/125
1/(5^x) = 1/(5^3)
x = 3
1/(5^x) = 1/125
1/(5^x) = 1/(5^3)
x = 3
2009-08-12 5:25 pm
1\5^x=1\125
on equating
5^x=125
also we can wright
5^x=5^3
base is equal so power is also
x=3
on equating
5^x=125
also we can wright
5^x=5^3
base is equal so power is also
x=3
2009-08-12 5:21 pm
realie 5^3=125
Solution 1:
5^-x = 1/125
5^-x=5^-3
therefore, x=3
solution 2:
take a log base 5 of both sides.
log base 5 (5^-x)
=log base (1/125)
-x=-3
so x=3
Solution 1:
5^-x = 1/125
5^-x=5^-3
therefore, x=3
solution 2:
take a log base 5 of both sides.
log base 5 (5^-x)
=log base (1/125)
-x=-3
so x=3
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