Dose any one knows how to do these pre calculus problems

1. If log_ x 128 = 9/9, then x =

2. If 10^{3 x + 7} = 4, then x =

3. The equation 7 x^{7}e^{-3 x} - 4 x^{8}e^{-3 x}= 0 has two roots.

The smaller root is _________

and the bigger root is ________

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You can tell right away that x=0 is one solution.
The other is x=7/4
http://www.flickr.com/photos/dwread/6334…