Đáp án:
a) ` x \ in \ {-2;0;2;4}`
b) ` x \ in \ {-8;-4;-2;2}`
c) ` x \ in \ {-4;-2;-1;1}`
Giải thích các bước giải:
a) `A in ZZ <=> 3 \ vdots \ x-1`
`to x-1 \ in \ Ư(3)={-3;-1;1;3}`
`to x \ in \ {-2;0;2;4}`
b) `B in ZZ <=> x-2 \ vdots \ x+3`
`to x+3-5 \ vdots \ x+3`
`to 5 \ vdots \ x+3`
`to x+3 \ in \ Ư(5)={-5;-1;1;5}`
`to x \ in \ {-8;-4;-2;2}`
c) `C in ZZ <=> 4x+1 \ vdots \ 2x+3`
`to 4x+6-5 \ vdots \ 2x+3`
`to 2.(2x+3)-5 \ vdots \ 2x+3`
`to 5 \ vdots \ 2x+3`
`to 2x+3 \ in \ Ư(5)={-5;-1;1;5}`
`to 2x \ in \ {-8;-4;-2;2}`
`to x \ in \ {-4;-2;-1;1}`
