Tìm x, biết rằng:
1) ( 2x + 1)3 = -0,001
2) ( 2x -3 )4 = ( 2x-3 )6
3) ( 2x+1 )5 = ( 2x+1)2010
4) \(\dfrac{8}{25}=\dfrac{2^x}{5^{x-1}}\)
5) 9x : 3x = 3
6) \(3^x+3^{x+3}=756\)
7) \(5^{x+1}+6.5^{x+1}=875\)
8) \(2^{x-1}.3^{y+1}=12^{x+9}\)
9) \(3^x=9^{y-1}\)
10) \(2^{x+1}.5^y=20^x\)
11) 15x : 3y = 75y
12) \(\dfrac{3}{5}:\dfrac{2x}{15}=\dfrac{1}{2}:\dfrac{4}{5}\)
13) \(\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{4}\) và xy + yz + zx = 104