tìm x
a/ \(\dfrac{5^x}{125}\)= 25\(^4\) b/ \(\dfrac{3^x}{3}\)+ 3\(^{x-2}\) = 4
c/ (x + \(\dfrac{2006}{2007}\))\(^6\) =0 d/ (x-\(\dfrac{1}{5}\))\(^3\)= \(\dfrac{8}{125}\)
e/ 3\(^x\) + 3\(^{x-2}\)= 810 g/ 5\(^{x+2}\) +5\(^{x+1}\) +5\(^x\) = 19375
giúp mk nha các bn mk