2007-11-04 08:45:39 · 22 answers · asked by HaZiM 1 in Science & Mathematics ➔ Mathematics
whats the lcm of 4,7,12,and 21. and also, whats the lcm of 2,3,5,7,11. i've tried all day but cant get it. thx
2007-11-04 08:46:40 · update #1
To get the LCM of 4, 7 and 12. Do them two at a time.
Use the fact that LCM of a and b = a*b/GCF(a.b).
This shows that if a and b have no prime factor
in common LCM of a and b is just their product.
So:
LCM of 4 and 7 = 28
LCM 28 and 12 = 28*12/4 = 28*3 = 84.
For the second question LCM of 21 and 84 is 21*84/21 = 84.
Finally, 2,3,5,7 and 11 are all prime numbers.
Since no 2 of these have a factor in common,
their LCM is2*3*5*7*11 = 2310.
2007-11-04 08:53:26 · answer #1 · answered by steiner1745 7 · 0⤊ 0⤋
3
2007-11-04 08:57:15 · answer #2 · answered by m.barrettsmith 2 · 0⤊ 0⤋
the LCM of 4, 7, and 12 is 84.
2007-11-04 08:58:59 · answer #3 · answered by nikkiebushnell 3 · 0⤊ 0⤋
84
2007-11-06 22:42:56 · answer #4 · answered by Anonymous · 0⤊ 0⤋
84
2007-11-06 06:46:12 · answer #5 · answered by dpdudeforever 1 · 0⤊ 0⤋
84
2007-11-04 08:51:36 · answer #6 · answered by Anonymous · 0⤊ 0⤋
84
2007-11-04 08:50:05 · answer #7 · answered by christiantb 2 · 0⤊ 0⤋
84
2007-11-04 08:48:37 · answer #8 · answered by ♥♥ 5 · 0⤊ 0⤋
84
2007-11-04 08:47:44 · answer #9 · answered by Questioning Machine 3 · 0⤊ 0⤋
4 = 2*2
7 = 7*1
12=2*2*3
LCM = 4*7*3 = 84
LCM of 3,4,7,21 is also 84
2*3*5*7*11 = 2310 = LCM of 2,3,5,7,11
2007-11-04 08:50:04 · answer #10 · answered by ironduke8159 7 · 0⤊ 0⤋