a,

56=2³.7

140=2².5.7

=>ƯCLN(56,140)=2².7=28

60=2².3.5

180=2².3².5

=>ƯCLN(60,180)=2².3.5=60

b,

84=2².3.7

108=2².3³

=>BCNN(84,108)=2².3³.7=756

24=2³.3

40=2³.5

168=2³.3.7

=>BCNN(24,40,168)=2³.3.5.7=840

Tick giúp mình với nhá!

168=2^3.3.7

180= 2^2.5.3^2

UCLN= 2^2.3=12

a) 15= 3.5

21= 3.7

ƯCLN(15,21)={3}

b)24=2^3.3

84=2^2.3.7

140=2^2.5.7

ƯCLN(2^2)={4}

Tìm x εIN biết
a) 390 - (x-8) = 168:13
b) (x-140) : 7 = 27 - 24
c) x- 6 :2 - ( 48 - 24 ) :2 :6 - 3 = 0
d) x+5.2-(32+16.3:6-15)=0

b) \(\left(x-140\right):7=27-24\)

\(\left(x-140\right):7=3\)

\(x-140=21\)

\(x=161\)

      vay   \(x=161\)

c) \(x-6:2-\left(48-24\right):2:6-3=0\)

\(x-3-24:2:6-3=0\)

\(x-3-2-3=0\)

\(x-8=0\)

\(x=8\)

vay \(x=8\)

d) \(x+5.2-\left(32+16.3:6-15\right)=0\)

\(x+10-\left(32+8-15\right)=0\)

\(x+10-25=0\)

\(x-15=0\)

\(x=15\)

vay \(x=15\)

a) \(390-\left(x-8\right)=168:13\)

\(390-x+8=\frac{168}{13}\)

\(x+8=390-\frac{168}{13}\)

\(x+8=\frac{5070}{13}-\frac{168}{13}\)

\(x+8=\frac{4902}{13}\)

\(x=\frac{4902}{13}-8\)

\(x=\frac{4798}{13}\)

vay \(x=\frac{4798}{13}\)

Bay lên rồi đây bạn thân!

a) Ta có 56 = 2³ . 7; 140 = 2² . 5 . 7. Do đó ƯCLN (56, 140) =  2²  . 7 = 28;

b) Ta có  24 = 2³ . 3; 84 = 2² . 3 . 7; 180 = 2² . 3² . 5.

Vậy ƯCLN (24, 84, 180) =  2² . 3 = 12.

c) Vì 180  60 nên ƯCLN (60, 180) = 60;

d) ƯCLN (15, 19) = 1

Chúc bạn học tốt nhé! 

a) Ta có 56 = 2³ . 7; 140 = 2². 5 . 7. Do đó ƯCLN (56, 140) =  2²  . 7 = 28;

b) Ta có  24 = 2³ . 3; 84 = 2² . 3 . 7; 180 = 2² . 3² . 5.

Vậy ƯCLN (24, 84, 180) =  2² . 3 = 12.

c) Vì 180⋮60 nên ƯCLN (60, 180) = 60;

d) ƯCLN (15, 19) = 1.

a)ƯCLN(15,21)=3x5x7=105

=>ƯC(15,21)=Ư(105)={1;3;5;7;15;21;35,105}

b)ƯCLN(24,84,140)=\(2^2\)

=>ƯC(24;84;140)=Ư(4)={1;2;4}

a. Ta có:

\(15=3.5\)\(;\)\(21=3.7\)

\(\Rightarrow\left(15;21\right)=3\)

\(\Rightarrow\text{Ư}c\left(15;21\right)=\text{Ư}\left(3\right)=\left\{\text{{}\pm1;\pm3\right\}\text{ }\)

b. Ta có

Tương tự a

các bạn giải giúp mik nhé

a) 15= 3.5

     21=3.7

ƯCLN(15;21)=3

ƯCLN(15;21)=Ư(3)={1;3}

Ta có: 120 = 2^3 x 3 x 5

          78 = 2 x 3 x 13

          168 = 2^3 x 3 x 7

=> ƯCLN(120;78;168) = 2 x 3 = 6

Vì 168\(⋮\)x;120\(⋮\)x;144\(⋮\)x=>xϵƯC(168;120;144)

ta có :

168=2³.3.7

120=2³.3.5

144=2⁴.3²

=>ƯCLN(168;120;144)=2³.3=24

=>ƯC(168;120;144)=Ư(24)={1;2;3;4;6;8;12;24}

Mà 5<x<25=>xϵ{6;8;12;24}

Vì 60\(⋮\)x và 132\(⋮\)x=>xϵƯC(60;132)

ta có :

60=2².3.5

132=2².3.11

=>ƯCLN(60;132)=2².3=12

=>ƯC(60;132)=Ư(12)={1;2;3;4;6;12}

Mà 2\(\le\)x<12=>xϵ{2;3;4;6}