Bài 3:
\(a,\Rightarrow3x=9\Rightarrow x=3\\ b,\Rightarrow x-5=12\Rightarrow x=20\\ c,\Rightarrow2x-1=3^2=9\Rightarrow2x=10\Rightarrow x=5\\ d,\Rightarrow5^{4x+5}=3125=5^5\Rightarrow4x+5=5\Rightarrow x=0\\ e,\Rightarrow5\cdot3^x=3^{11}\left(7\cdot3+24\right)=3^{11}\cdot45=3^{11}\cdot3^2\cdot5\\ \Rightarrow x=11+2=13\\ f,\Rightarrow5^x\left(1+5^2\right)=600+25\cdot2=650\\ \Rightarrow5^x=\dfrac{650}{26}=25=5^2\Rightarrow x=2\)
Bài 4:
\(a,\Rightarrow x=68-345=-277\\ b,\Rightarrow7x=84\Rightarrow x=12\\ c,\Rightarrow x^2-26=280:28=10\Rightarrow x^2=36\Rightarrow\left[{}\begin{matrix}x=6\\x=-6\end{matrix}\right.\\ d,\Rightarrow\left(x-1\right)^4=81\Rightarrow\left[{}\begin{matrix}x-1=3\\x-1=-3\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=4\\x=-2\end{matrix}\right.\\ e,\Rightarrow\left[{}\begin{matrix}5x-10=0\\6x+18=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=2\\x=-3\end{matrix}\right.\\ f,\Rightarrow3^x\left(1+3+3^2\right)=3^x\cdot13=13\Rightarrow3^x=1=3^0\Rightarrow x=0\)
Bài 5:
\(a,x\inƯ\left(17\right)=\left\{-17;-1;1;17\right\}\\ b,\Rightarrow2\left(x+1\right)-5⋮x+1\\ \Rightarrow x+1\inƯ\left(5\right)=\left\{-5;-1;1;5\right\}\\ \Rightarrow x\in\left\{-6;-2;0;4\right\}\\ c,\Rightarrow3x-6⋮3x-2\\ \Rightarrow3x-2-4⋮3x-2\\ \Rightarrow3x-2\inƯ\left(4\right)=\left\{-4;-2;-1;1;2;4\right\}\\ \Rightarrow3x\in\left\{-2;0;1;3;4;6\right\}\\ \Rightarrow x\in\left\{-\dfrac{2}{3};0;\dfrac{1}{3};1;\dfrac{4}{3};2\right\}\)