a) 40=2³.5

60=2².3.5; ƯCLN(40,60)=2².5=20

b)36=2².3²

60=2².3.5; ƯCLN(36,60)=2².3=12

c)13=13

20=2².5; ƯCLN(13,20)=1

d)28=2².7

39=3.13

35=5.7; ƯCLN(28,39,35)=1

a) 40=2³.5

60=2².3.5; ƯCLN(40,60)=2².5=20

b)36=2².3²

60=2².3.5; ƯCLN(36,60)=2².3=12

c)13=13

20=2².5; ƯCLN(13,20)=1

d)28=2².7

a) UCLN(40, 60)

Ta có: 40 = 2³.5

60 = 2².3.5

UCLN(40, 60) = 2².5 = 20

b) UCLN(13, 20)

Ta có: 13 = 13

20 = 2².5

UCLN(13, 20) = 1

c) UCLN(36, 60, 72)

Ta có: 36 = 2².3²

60 = 2².3.5

72 = 2³.3²

UCLN(36, 60, 70) = 2².3 = 12

d) UCLN(28, 39, 35)

Ta có: 28 = 2².7

39 = 39

35 = 5.7

UCLN(28, 39, 35) = 1

a) ƯCLN(40; 60)=20

b) ƯCLN(36; 60; 72)=12

c) ƯCLN(13;20)=1

d) ƯCLN(28; 39; 35;)=1

a, 40=2³.5

60=2².3.5

ƯCLN(40;60)=2².5=20

b, 36=2².3²

60=2².3.5

72=2³.3²

ƯCLN(36;60;72)=2².3=12

c, 13=13

20=2².5

ƯCLN(13;20)=1

d, 28=2².7

39=3.13

35=5.7

ƯCLN(28;39;35)=1

Chúc bạn học giỏi nha!!!!

a) 28 = 2 2 . 7 ; 70 = 2.5.7 .Vậy ƯCLN(28,70) = 2.7 = 14

b) ƯCLN(36, 60,72) =12

c) ƯCLN(60,180) = 60

d) ƯCLN(28, 39, 35) = 1

a) 40 = 2³.5

60 = 2².3.5

ƯCLN(40; 60) = 2².5 = 20

ƯC(40; 60) = Ư(20) = {1; 2 ; 4; 5; 10; 20}

b) 28 = 2².7

39 = 3.13

35 = 5.7

ƯCLN(28; 39; 35) = 1

ƯC(28; 39; 35) = Ư(1) = 1

c) 48 = 2⁴.3

60 = 2².3.5

120 = 2³.3.5

ƯCLN(48; 60; 120) = 2².3 = 12

ƯC(48; 60; 120) = Ư(12) = {1; 2; 3; 4; 6; 12}

d) 30 = 2.3.5

75 = 3.5²

135 = 3³.5

ƯCLN(30; 75; 135) = 3.5 = 15

ƯC(30; 75; 135) = Ư(15) = {1; 3; 5; 15}

a) 20

b) ko pk là 39 mà là 49 ⇒ ƯCLN là 7

c)12

d)15

a/20            b/12    c/1   d/1        

a) 40 và 60
Ta có Ư(40)\(\in\){1;2;4;5;6;8;10;16;20}
          Ư(60)\(\in\){1;2;3;4;5;6;10;12;15;20;30)
     ƯC(40;60)\(\in\){1;2;3;4;5;6;10;20}
Trong đó,20 là ƯCLN.Vậy ƯCLN(40;60)\(\in\){20}
b)