\(ƯC\left(8,12\right)=\left\{\pm1;\pm2;\pm4\right\}\)

\(ƯC\left(12;15;30\right)=\left\{\pm1;\pm3\right\}\)

\(ƯC\left(60;72\right)=\left\{\pm1;\pm2;\pm3;\pm4;\pm6;\pm12\right\}\)

\(ƯC\left(24;42\right)=\left\{\pm1;\pm2;\pm3;\pm6\right\}\)

DỄ vl ......!

a) { 1; 2; 4 }

b) { 1; 3 }

c) { 1; 2; 3; 4; 6; 12 }

d) { 1; 2; 3; 6 }

sai lớp rồi kìa

a) Ư(8) = { 1; 2; 4; 8; -1; -2; -4; -8 }

    Ư(12) = { 1; 2; 3; 4; 6 ;12; -1; -2; -3; -4; -6; -12 }

Vậy ƯC(8; 12) = { 1; 2; 4; -1; -2; -4 }

b) Ư(12) = { 1; 2; 3; 4; 6 ;12; -1; -2; -3; -4; -6; -12 }

    Ư(15) = { 1; 3; 5; 15; -1; -3; -5; -15 }

    Ư(30) = { 1; 2; 3; 5; 10; 15; 30; -1; -2; -3; -5; -10; -15; -30 }

Vậy ƯC(12; 15; 30) = { 1; 3; -1; -3 }

c) Ư(60) = { 1; 2; 3; 4; 5; 6; 10; 15; 20; 30; 60; -1; -2; -3; -4; -5; -6; -10; -15; -20; -30; -60 }

    Ư(72) = { 1; 2; 3; 4; 6; 8; 9; 12; 18; 24; 36; 72; -1; -2; -3; -4; -6; -8; -9; -12; -18; -24; -36; -72 }

Vậy ƯC(60 ; 72) = { 1; 2; 3; 4; 6; -1; -2; -3; -4; -6 }

d) Ư(24) = { 1; 2; 3; 4; 6; 8; 12; 24; -1; -2; -3; -4; -6; -8; -12; -24 }

    Ư(42) = { 1; 2; 3; 6; 7; 14; 21; 42; -1; -2; -3; -6; -7; -14; -21; 42 }

Vậy ƯC(24; 42) = { 1; 2; 3; 6; -1; -2; -3; -6 }

Co :60=2².3.5

72=2³.3²

»UCLN(60,72)=2².3=12

»UC (60,72)=U(12)={1,2,3,4,6,12}.

a: \(Ư\left(16\right)=\left\{1;2;4;8;16\right\}\)

\(Ư\left(24\right)=\left\{1;2;3;4;6;8;12;24\right\}\)

\(ƯC\left(16;24\right)=\left\{1;2;4;8\right\}\)

b: \(Ư\left(20\right)=\left\{1;2;4;5;10;20\right\}\)

\(Ư\left(32\right)=\left\{1;2;4;8;16;32\right\}\)

\(ƯC\left(20;32\right)=\left\{1;2;4\right\}\)

Bài 2

a) ta gọi các số thuộc ƯC(16;24) là A ta có

\(A\in\left\{1;2;4;8\right\}\)

b)ta gọi các số thuộc ƯC(60;90) là B ta có

\(B\in\left\{1;2;3;5;6;10;15;30\right\}\)

Bài 3

a) gọi các số thuộc BC (13;15) là A

\(A\in\left\{195;390;585;780;...\right\}\)

b)gọi các số thuộc BC (10;12,15) là B

\(B\in\left\{60;120;180;240;300;...\right\}\)

bài 4

a)10=2.5

28=2².7

=> ƯCLN(10;28)=2².5.7=140

b) ƯCLN =16 vì 80 chia hết cho 16 , 176 chia hết cho 16

a)bài 5

16= 2⁴

24=2³.3

BCNN = 2⁴.3=48

b)8=2³

10=2.5

20=2².5

BCNN(8;10;20)=2³.5=40

c)8=2³

9=3²

11=11

BCNN(8;9;11)=2³.3².11

ƯC ( 8 , 12 ) = { ± 1 ; ± 2 ; ± 4 } 

ƯC ( 12 ; 15 ; 30 ) = { ± 1 ; ± 3 }

Ư C ( 60 ; 72 ) = { ± 1 ; ± 2 ; ± 3 ; ± 4 ; ± 6 ; ± 12 }

Ư C ( 24 ; 42 ) = { ± 1 ; ± 2 ; ± 3 ; ± 6 }

a) Ư(8) = {1;2;4;8}; Ư(12) = {1;2;3;4;6;12} => ƯC(8;12) = {1;2;4;}

b) Ư(24) = {1;2;3;4;6;8;12;24}; Ư(32) = {1;2;4;8;16;32} => ƯC(24; 32) = {1;2;4;8;}

c) Ư(7) = {1;7} ; Ư(10) = {1;2;5;10} => ƯC(7;10) = {1}

d) 8 = 2³; 10 = 2.5 => BCNN (8;10) = 2³.5 = 40 => BC(8;10) = B(40) = {0;40;80;...}

e) 25 = 5² => BCNN(2;3;25) = 2.3.5² = 150 => BC (2;3;25) = B(150) = {0;150; 300; ...}

2) N = {0;1;2;3;...}; N* = {1;2;3;....} => N giao N* = {1;2;3;...} = N*

a) Ư(8) = {1;2;4;8}; Ư(12) = {1;2;3;4;6;12} => ƯC(8;12) = {1;2;4;}

Vâu b,c,d,e tương tự nha bn

2) N = {0;1;2;3;...}; N* = {1;2;3;....} => N giao N* = {1;2;3;...} = N*

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