tim BCNN (8,12)
BCNN(5,7,8)
BCNN(12,16,48)
Tìm BCNN (8,12) : BCNN (5,7,8) : BCNN (12,16,48)
Ta có : 8 = 2^3
12 = 2^2 x 3
BCNN ( 8,12) = 2^3 x 3 = 24
Ta có : 5 = 5
7 = 7
8 = 2^3
BCNN ( 5,7,8 ) = 5 x 7 x 2^3 = 280
Ta có : 12 = 2^2 x 3
16 = 2^4
48 = 2^4 x 3
BCNN ( 12 ,16,48) = 2^4 x 3 = 48
1. BCNN(15,18) là:
A. 270. B. 18. C. 90. D. 180.
2..BCNN(12,16,48) là:
A. 12 B. 16 C. 48 D. 0
3. BCNN(15,20,50) là:
A. 100. B. 200. C. 300. D. 400.
giúp em hết câu này ạ
Câu 1: C
Câu 2: C
Câu 3: C
1.Hãy tìm các tập B(8),B(120) và BC(8,12)
2.Hãy tìm BCNN(105,140) rồi tìm BC(105,140)
1. B(8)=(8,16,24,32,40,48...) B(120)=(120,240,480,960...) BC(8,12)= (0,24,48...)
2.BCNN(105,140)=420 và BC(105,140)=B(420)=(0,420,840...)
Biet rang : BCNN(a,b).UCLN(a,b)
a, BCNN cua hai so la 600, UCLN cua chung nho hon 10 lan BCNN. So thu 1 la 120, tim so thu 2.
b, UCLN cua hai so la 12, BCNN cua chung lon gap 6 lan UCLN . So t 1 la 24, tim so t 2
c, Tong cua hai so bang 60, tong giua UCLN va BCNN cua chung la 84. Tim hai so do.
Tim BCNN(22;24;32)
22=
24=
32=
BCNN(22;24;32)=…....
Ok
ta có :
22 = 2 . 11
24 = 23 . 3
32 = 25
=> BCNN(22;24;32)= 25 . 3 . 11 = 1056
vậy : BCNN(22;24;32)= 1056
Tim BCNN(22;24;32)
22 = 2.11
24 = 23.3
32 = 25
BCNN(22;24;32) = 25.11.3 = 1056
Tim BCNN(22;24;32)
22 = 2.11
24 = 23.3
32 = 25
BCNN(22;24;32) = 25.11.3 = 1056
BCNN 15;25 . b, ( ) BCNN 7;13 . c, ( ) BCNN 8;9;11 . a, ( ) BCNN 40;52 . b, ( ) BCNN 13;15 . c, ( ) BCNN 10;12;15 . a, ( ) BCNN 60;280 . b, ( ) BCNN 11;55 . c, ( ) BCNN 16;25;32 . a, ( ) BCNN 84;108 . b, ( ) BCNN 25;39 . c, ( ) BCNN 28;56;560 . a, ( ) BCNN 154;220 . b, ( ) BCNN 12;36 . c, ( ) BCNN 24;40;168 . a, ( ) BCNN 770;220 . b, ( ) BCNN 13;39 . c, ( ) BCNN 100;120;140 .
BCNN 15;25 . b, ( ) BCNN 7;13 . c, ( ) BCNN 8;9;11 . a, ( ) BCNN 40;52 . b, ( ) BCNN 13;15 . c, ( ) BCNN 10;12;15 . a, ( ) BCNN 60;280 . b, ( ) BCNN 11;55 . c, ( ) BCNN 16;25;32 . a, ( ) BCNN 84;108 . b, ( ) BCNN 25;39 . c, ( ) BCNN 28;56;560 . a, ( ) BCNN 154;220 . b, ( ) BCNN 12;36 . c, ( ) BCNN 24;40;168 . a, ( ) BCNN 770;220 . b, ( ) BCNN 13;39 . c, ( ) BCNN 100;120;140 .
biet BCNN(a,b)=1995
BCNN(a,c)=1998
tim a ,b,c
Tìm BCNN:
a, BCNN ( 8, 10, 20 )
b, BCNN (16, 24 )
c, BCNN ( 60, 140 )
d, BCNN ( 8, 9, 11 )
e, BCNN ( 24, 40, 162 )
f, BCNN ( 56, 70, 162 )
g, BCNN (28, 30 20 )
h, BCNN ( 34, 32, 20 )
k, BCNN ( 42, 70, 52 )
I, BCNN ( 9, 10, 11 )
Ta có:8=23
10=2.5
24=24.5
BCNN(...)=23.5=24.5=40
b)Ta có:
16=24
24=23.3
BCNN(...)=24.3=48
c)Ta có:
60=22.3.5
140=22.5.7
BCNN(...)=22.3.5.7=420
Mấy bài sau bn cứ lm như thế này nhé^^