SOLUTION: I need help with these questions 5^x=125 8^x+1=16^x 81^(3/4)=x 8^(-2/3)=x

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Question 492608: I need help with these questions
5^x=125
8^x+1=16^x
81^(3/4)=x
8^(-2/3)=x
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
solving for x:
..
5^x=125
5^x=5^3
x=3
..
8^x+1=16^x
don't know how to do the algebra on this one.
My graphing program gives and answer of x=.464968..
..
81^(3/4)=x
Take the 4th root of 81 and cube it
81^(1/4)=3
3^2=9
x=9
..
8^(-2/3)=x
Take the cube root of 8 and raise it to -2 power
8^1/3=2
2^-2=1/2^2=1/4
x=1/4