B(_-15)={0;-15;15;-30;30;...}

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

ƯC_(-12;18)={-6;-4;-3;-2;-1;1;2;3;4;6}

BC_-15;20)={0;-60;60;-120;120;...}

B(-15)={...,-45,-30,-15,0,15,30,45,...}

U(-24)={-24,-12,-8,-6,-4,-3,-2,-1,1,2,3,4,6,8,12,24}

UC(-12;18)={-6,-3,-2,-1,1,2,3,6}

BC(-15;20)={-5,-1,1,5} 

Ta có : \(108=2^2.3^3\)

             \(2^3.3^2.5\)

=> ƯCLN(108;180 ) = \(2^2.3^2\) = 36

Mà Ư(36) = { 1 ; 2; 3 ; 4 ;6 ;9 ; 12 ;18 ; 36 }

=> ƯC(108;180) > 15 = { 18 ; 36 } 

\(Tac\text{ó}:108=2^2.3^3\\ 180=2^3.3^2.5\\ =>UCLN\left(108;80\right)=2^2.3^2=36\\ M\text{à}\text{Ư}\left(36\right)=\left\{1;2;3;4;6;9;12;18;36\right\}\)

=>ƯC(108;180)>15={18;36)

108=2^2.3^3

180=2^2.3^2.5

=)UCLN(108;180)=2^2.3^2=36 Ư(36)= 1;2;3;4;6;9;12;18;36

=) ƯC(108;180)=1;2;3;4;6;9;12;18;36

Mà ước chung lại>15

UC (108;180)ϵ18;36

HAHA 

BN GIUP MK HOI A 

THANK NHIU

12 = 2².3

27 = 3³

ƯCLN(12; 27) = 3

ƯC(12; 27) = Ư(3) = {1; 3}

--------

6 = 2.3

15 = 3.5

ƯCLN(6; 15) = 3

ƯC(6; 15) = Ư(3) = {1; 3}

--------

21 = 3.7

10 = 2.5

12 = 2².3

ƯCLN(21; 10; 12) = 1

ƯC(21; 10; 12) = Ư(1) = {1}

Câu hỏi của Victory - Toán lớp 6 - Học toán với OnlineMath

tim uc cua 24 va 70  

24=2³.3²

70=2.5.7

=> UCLN( 24;70) = 2

mà UC (24;70) = U(2)= {1;2}

Ta có:

84 = 2² x 3 x 7

216 = 2³ x 3³

168 = 2³ x 3 x 7 

=> UCLN ( 84; 216; 168 ) = 2² x 3 = 12

=> ƯC ( 84; 216; 168 ) = { 1; 2; 3; 4; 6; 12 }

TA CÓ : 84 = 2 MŨ 2 .3.7

            216=2 MŨ 3 . 3 MŨ 3

           168=2 MŨ 3 .3 .7

ƯLCN ( 84 , 216 , 168 ) = 2 MŨ 2 .3 = 12

ƯC ( 84,216,168) = Ư ( 12) = 1 ; 2 ; 3;4;6;12

84 = 2² . 3 . 7

216 = 2³ . 3³

168 = 2³ . 3 . 7

ƯCLN ( 84 ; 216 ; 168 ) = 2² . 3 = 12

ƯC ( 84 ; 216 ; 168 ) = { 1 ; 2 ; 3 ; 4 ; 6 ; 12 }

Nhớ k cho mình nha :3 :)) :D