1, Để
\(27⋮x=>x\inƯ\left(27\right)\\ =>x=\left\{1;-1;3;-3;9;-9;27;-27\right\}\\ 4,⋮x-1\\ =>x-1\inƯ\left(4\right)\\ Ư\left(4\right)=\left\{1;-1;2;-2;4;-4\right\}=>x=\left\{2;0;3;-1;5;-3\right\}\\ 3,5⋮x+1=>x+1\inƯ\left(5\right)\\ Ư\left(5\right)=\left\{1;-1;5;-5\right\}\\ =>x=\left\{0;-2;4;-6\right\}\)

4 và 5