a, Ta có: 24 =  2 3 . 3 ; 10 = 2.5

=> ƯCLN(24;10) = 2

BCNN(24;10) =  2 3 . 3 .5 = 120

b, Ta có: 150 =  2 . 3 . 5 2 ; 84 =  2 2 . 3 . 7

=> ƯCLN(150;84) = 2.3 = 6

BCNN(150;84) =  2 2 . 3 . 5 2 . 7

c, Ta có: 140 =  2 2 . 5 . 7 ; 210 = 2.3.5.7; 56 =  2 3 . 7

=> ƯCLN(140;210;56) = 2.7 = 14

BCNN(140;210;56) =  2 3 . 3 . 5 . 7 = 840

d, Ta có: 105 = 3.5.7; 84 =  2 2 . 3 . 7 ; 30 = 2.3.5

=> ƯCLN(105;84;30) = 3

BCNN(105;84;30) =  2 2 . 3 . 5 . 7 = 420

b: UCLN(18;42)=6

24 = 2³.3;  36 = 2⁴.3⁴; 60 = 2².3.5

ƯCLN( 24; 36; 60) = 2².3 = 12

12 = 2².3; 15 = 3.5; 10 = 2.5 

ƯCLN(12; 15; 10) = 1

24  = 2³.3; 16 = 2⁴; 8 = 2³

ƯCLN(24; 16; 8) = 2³

9 = 3²; 81 = 3⁴ 

ƯCLN( 9; 81) =  9

11 = 11; 15 = 3.5

ƯCLN( 11; 15) = 1

1 = 1; 10 = 2.5

ƯCLN(1; 10) = 1

150 = 2.3.5²;  84 = 2².3.7 

ƯCLN( 150; 84) = 6

5: \(16=2^4;32=2^5;112=2^4\cdot7\)

=>ƯCLN(16;32;112)=\(2^4=16\) ; BCNN(16;32;112)=\(2^5\cdot7=32\cdot7=224\)

6: \(25=5^2;55=5\cdot11;75=5^2\cdot3\)

=>ƯCLN(25;55;75)=5; BCNN(25;55;75)=\(5^2\cdot3\cdot11=33\cdot25=825\)

7: \(150=2\cdot3\cdot5^2;84=2^2\cdot3\cdot7;30=2\cdot3\cdot5\)

=>ƯCLN(150;84;30)=\(2\cdot3=6\) ; BCNN(150;84;30)=\(2^2\cdot3\cdot5^2\cdot7=10^2\cdot3\cdot7=2100\)

8: \(12=2^2\cdot3;15=3\cdot5;10=2\cdot5\)

=>ƯCLN(12;15;10)=1; BCNN(12;15;10)=\(2^2\cdot3\cdot5=4\cdot3\cdot5=60\)

a) Ta có :

9 = 3²

81 = 3⁴

=> ƯCLN ( 9 ; 81 ) = 3² = 9

b) Ta có :

11 = 11

15 = 3 . 5

=> ƯCLN ( 11 ; 15 ) = 1

c) Ta có :

10 = 2 . 5

1 = 1

=> ƯCLN ( 1 ; 10 ) = 1

d) Ta có :

150 = 2 . 3 . 5²

84 = 2² . 3 . 7

=> ƯCLN ( 150 ; 84 ) = 2 . 3 = 6

a,9

b,1

c,1

d,6

a, Có 16 = 2 4 ; 18 = 2 . 3 2 ; 176 =

Nên UCLN(16,18,176) = 2

b, Có 18 =  2 . 3 2 ; 30 = 2.3.5; 72 =  2 3 . 3 2

Nên UCLN(18,30,72) = 2.3 = 6

c, Có 26 = 2.13; 39 = 3.13; 48 =  2 4 . 3

Nên UCLN(26,39,48) = 1

d, Có 150 =  2 . 3 . 5 2 ; 84 =  2 2 . 3 . 7 ; 30 = 2.3.5

Nên UCLN(150,84,48) = 2.3 = 6