SOLUTION: This question has been bothering me for quite a while now. 4 x 5^(X+2) = 5 x 4^(2X) (big 'X' is the variable, solve for X) I tried taking the log of both sides to get l

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: This question has been bothering me for quite a while now. 4 x 5^(X+2) = 5 x 4^(2X) (big 'X' is the variable, solve for X) I tried taking the log of both sides to get l      Log On


   



Question 37055: This question has been bothering me for quite a while now.
4 x 5^(X+2) = 5 x 4^(2X)
(big 'X' is the variable, solve for X)
I tried taking the log of both sides to get
log 4 + (X+2)log 5 = log 5 + (2X)log 4
then group like terms
(X+2)log 5 - (2X)log 4 = log 5 - log 4
then I get stuck...
any help?

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
4 x 5^(X+2) = 5 x 4^(2X)
Take the log of both sides to get:
log4+(x+2)log5 = log5+(2x)log4
log4+xlog5+2log5= log5+(2x)log4
x(log5-2log4)=-(log5+log4)
x(-0.50514998)=-1.30103000
x= -2.57553211
Cheers,
stan H.