a)60

B)729

c)840

a)10 = 2*5; 12 = 2² *3; 15 = 3*5

BCNN(10, 12, 15) = 2² *3*5 = 60

b) 8 = 2³; 9 = 3²; 11 = 11

BCNN(8, 9, 11) = 8*9*11 = 792

c) 24 = 2³ *3; 40 = 2^{3 *}5; 168 = 2³ *3*7

BCNN(24, 40, 168) = 2³ *3*5*7 = 840.

a)    10 = 2 . 5, 12 = 2² . 3, 15 = 3 . 5. BCNN (10, 12, 15) = 2² . 3 . 5 = 60;

b)    BCNN (8, 9, 11) = 8 . 9 . 11 = 792;

c)    Ta có 24 = 2³ . 3, 40 = 2³ . 5, 168 = 2³ . 3 . 7.

BCNN (24, 40, 168) = 2³ . 3 . 5 . 7 = 840.

10.2=20;

=>BCNN(20,15)={0;60;120;180;240;..}

BCNN(8,9,11)={0;88;176;264}

1) Ta có: 10 = 2.5

12 = 2².3

15 = 3.5

=> BCNN(10;12;15) = 2².3.5 = 60

2) Do 8;9;11 nguyên tố cùng nhau từng đôi một => BCNN(8;9;11) = 8.9.11 = 792

3) Ta có: 24 = 2³.3

40 = 2³.5

168 = 2³.3.7

=> BCNN(24;40;168) = 2³.3.5.7 = 840

BCNN(10,12,15) là:

10=2.5

12=2².3

15=3.5

=>BCNN(10,12,15)=2².3.5=60

BCNN(8,9,11):

8=2³

9=3²

11=11

=>BCNN(8,9,11)=2³.3².11=792

BCNN(24,40,168):

24=2³.3

40=2³.5

168=2³.3.7

=> BCNN(24;40;168)=2³.3.5.7=840

BCNN(10,12,15) là:

10=2.5

12=2².3

15=3.5

=>BCNN(10,12,15)=2².3.5=60

BCNN(8,9,11):

8=2³

9=3²

11=11

=>BCNN(8,9,11)=2³.3².11=792

BCNN(24,40,168):

24=2³.3

40=2³.5

168=2³.3.7

=> BCNN(24;40;168)=2³.3.5.7=840

1: a) Ta có 60 = 2³ . 3 . 5; 280 = 2² . 5 .7. BCNN (60, 280) = 2³ . 3 . 5 . 7 = 840.

b) Ta có 84 = 2² . 3 . 7; 108 = 2² . 3³.

 BCNN (84, 108) = 2² . 3³ . 7 = 756.

c) ĐS: BCNN (13, 15) = 195.

2:a)    10 = 2 . 5, 12 = 2² . 3, 15 = 3 . 5. BCNN (10, 12, 15) = 2² . 3 . 5 = 60;

b)    BCNN (8, 9, 11) = 8 . 9 . 11 = 792;

c)    Ta có 24 = 2³ . 3, 40 = 2³ . 5, 168 = 2³ . 3 . 7.

BCNN (24, 40, 168) = 2³ . 3 . 5 . 7 = 840.

840                         756                                            195

60                             792                                            840

BCNN (60;280) =840

BCNN (84;108)=756

BCNN (13;15) = 195

BCNN (10;12;15) = 60

BCNN (8;9;11) = 792

BCNN ( 24;40;168) = 640

a, Ta có : 10=2.5
               12=2^2 . 3
               15=3.5
=> BCNN(10,12,15)=2^2.3.5=60
b, Ta có : 8 = 2^3

              9 = 3^2
=>BCNN(8,9,11)=2^3 . 3^2 . 11 = 792
c, Ta có :  24=3. 2^3
                40=2^3.5
                168=2^3 .3.7
=>BCNN(24,40,168)=2^3 . 3.5.7=840

a ) 60        b ) 792         c ) 840

Phân tích :

24 =  2³ . 3

40 = 2³ . 5

168 = 2³ . 3. 7 

=> BCNN(24;40;168) = 2³ . 3 . 5 . 7 = 840

a)BCNN(10;12;15)=60

b)BCNN(8;9;11)=792

c)BCNN(24;40;168)=840

10;12;15

10=2.5

12=2^2.3

15=3.5

bcnn(10;12;15)=2^2.3.5=60

8;9;11

bcnn(8;9;110)=8.9.11=792

vì 3 số là số nguyên tố cùng nhau

24;40;168

20=2^2.5

40=2^3.5

168=2^3.3.7

bcnn(24;40;168)=2^3.5.7=280

10=2.5

12=2^2.3

^15=3.5

^BCNN:4.3.5

^8;9;11

vi 3 so deu la so nguyen to nen

BCNN:8.9,11=792

24;40;16

24=2^3.3

40=2^3.5

^{168=2.2.2.3.7}

UCLN:2^3.3=24

TSR=5.7

BCNN:24.5.7=4200

10=2.5

12=2².3

15=3.5

=>BCNN(10,12,15)=2².3.5=15

8=2³

9=3²

11=11

=>BCNN(8,9,11)=2³.3².11=792

24=2³.3

40=2³.5

168=2³.3.7

=>BCNN(24,40,168)=2³.3.5.7=840