how did you get your answer
2006-11-14 13:35:14 · 6 answers · asked by emily m 1 in Science & Mathematics ➔ Mathematics
2520
1260 x 2 = 2520
120 x 21 = 2520
2006-11-14 13:38:03 · answer #1 · answered by Anonymous · 0⤊ 0⤋
The lowest common multiple is the smallest number they will both divide into.
I'm going to start with an easy example. What is the lowest common multiple of 12 and 15
express each number in it's prime factors. ( you are looking for the smallest numbers, which multiplied together make 12 and 15.
12 = 2 x 2 x 3
15 = 3 x 5
the lowest common multiple must contain 2 x 2 x 3 (in the 12) x 5 (in the 15)
Multiplying these out LCM of 12 and 15 = 60
The smallest number that both 12 and 15 will divide into = 60
120 = 2 x 2 x 2 x 3 x 5
1260 = 2 x 2 x 3 x 3 x 5 x 7
LCM of 120 and 1260 is 2 x 2 x 2 x3 x 3 x 5 x 7
(It must contain three twos for the twelve, a three and a five)
You don't need any extra twos for the 1260 as there are already three of them. you need one extra 3 for 1260. The 5 is already present and you need an extra 7
The LCM of 120 and 1260 is 8 x 9 x 5 x 7
=360 x 7
=2520
2006-11-14 21:57:47 · answer #2 · answered by rosie recipe 7 · 0⤊ 0⤋
Least common multiple (LCM)
The least common multiple (LCM) of 2 numbers is the smallest number that they both divide evenly into. One good way to find the least common multiple of 2 numbers is to multiply both numbers by 1,2,3,4,5... and then find the first multiple that appears in both lists.
For example, find the least common multiple of 6 and 8:
Multiples of 6: 6 12 18 24 30 36 42 48 54 60
Multiples of 8: 8 16 24 32 40 48 56 64 72 80
The first number that appears in both lists is 24. (48 appears also, but it is not 'least'), so 24 is the LCM of 6 and 8.
Now, can you find the least common multiple of 1260 and 120 ?
Multiples of 1260: 1260, 2520, 3780, 5040......
Multiples of 120: 120, 240, 360, 480, 600, 720, 840, 960, 1080, 1200, 1320, 1440, 1560, 1680, 1800, 1920, 2040, 2160, 2280, 2400, 2520......
2520 is the LCM of 1260 and 120.
2006-11-14 22:04:34 · answer #3 · answered by Pam 5 · 0⤊ 0⤋
2520
1260/120 = 10.5
1260*2/120 = 21
1260*2 = 2520
2006-11-14 21:37:09 · answer #4 · answered by BurningPyre 4 · 0⤊ 0⤋
60
2006-11-14 21:38:09 · answer #5 · answered by Mark Antony 3 · 0⤊ 1⤋
60 is the GCD (greatest common demoninator)
120=60*2
1260=60*21
2 of course would be the LCD.
2006-11-14 21:38:18 · answer #6 · answered by bourqueno77 4 · 0⤊ 1⤋