i,(x-3).(x-3)3=81 =>(x-3)4=81 =>(x-3)4=34 =>x-3=3 =>x=3+3 =>x=6
k: |x-1|-x=x-5
=>|x-1|=2x-5
\(\Leftrightarrow\left\{{}\begin{matrix}x>=\dfrac{5}{2}\\\left(2x-5-x+1\right)\left(2x-5+x-1\right)=0\end{matrix}\right.\Leftrightarrow x\in\varnothing\)
p: |x+4|+x=12-x
=>|x+4|=12-2x
\(\Leftrightarrow\left\{{}\begin{matrix}x< =6\\\left(-2x+12+x+4\right)\left(-2x+12-x-4\right)=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x< =6\\\left(-x+16\right)\left(-3x+8\right)=0\end{matrix}\right.\Leftrightarrow x=16\)
z: \(\Leftrightarrow2^{3x-2-x+3}=2^{14}\)
=>2x+1=14
hay x=13/2