2007-11-04 16:52:15 · 10 answers · asked by Pretty 'n' Pink! 1 in Science & Mathematics ➔ Mathematics
The lowest common denominator is the smallest number that all three numbers will divide into with a whole number quotient.
The process used is to first break each number into its prime factors.
12 = 2x2x3, 15 = 3x5, and 21 = 3x7
The LCD will be 2x2x3x5x7 = 420
420/12 = 35, 420/15 = 28, and 420/21 = 20
35, 28, and 20 are whole numbers.
12, 15, and 21 also have a common factor, 3. Since it is the largest prime number that divides into all three numbers, it is called the largest common factor.
Sometimes the largest common denominator is confused with the largest common factor.
2007-11-04 17:08:35 · answer #1 · answered by TheProfessor 2 · 0⤊ 1⤋
Thanks for a very simple question. Follow my step below:
The lowest common denominator is the smallest number that all three numbers will divide into with a whole number quotient.
The process used is to first break each number into its prime factors.
12 = 2 x 2 x 3, 15 = 3 x 5, and 21 = 3 x 7
The Lowest common denominator will be 2 x 2 x 3 x 5 x 7 = 420
420/12 = 35, 420/15 = 28, and 420/21 = 20
35, 28, and 20 are whole numbers.
12, 15, and 21 also have a common factor, 3. Since it is the largest prime number that divides into all three numbers, it is called the largest common factor.
Sometimes the largest common denominator is confused with the largest common factor.
I hope you got the best answer for your question. Have a nice day!
2007-11-04 18:40:59 · answer #2 · answered by Nizam89 3 · 0⤊ 0⤋
The factors of 12:
1, 2, 3, 4, 6, 12
The factors of 15 :
1, 3, 5, 15
The factors of 21:
1, 3, 7, 21
The lowest common denominator of 12, 15 and 24 is 1.
All the numbers have lowest denominator as 1.
The other denominator of 12, 15 and 21 is:
3
Therefore,
The solution of denominators of 12, 15 and 21
= { 1, 3 }
Best of luck !
2007-11-04 16:55:44 · answer #3 · answered by Raut N 3 · 0⤊ 2⤋
factor of 12 : 2 * 2 * 3
factor of 15 : 3 * 5
factor of 21 : 3 * 7
The lowest common denominator is :
2 * 2 * 3 * 5 * 7 = 420
2007-11-04 17:03:29 · answer #4 · answered by Chan A 3 · 0⤊ 1⤋
12 = (2)(2)(3)
15 = (3)(5)
21 = (3)(7)
The lowest common denominator will be the common factors above (note they all contain a 3 so you only need to show it once)
(2)(2)(3)(5)(7) = 420
2007-11-04 16:58:02 · answer #5 · answered by Anonymous · 0⤊ 2⤋
The lcd is 420
420/12=35
420/15=28
420=21=20
2007-11-04 16:58:46 · answer #6 · answered by Matt 3 · 0⤊ 2⤋
12 = 3(4)
15 = 3(5)
21 = 3(7)
lcd = 3(4)(5)(7) = 420
2007-11-04 16:57:14 · answer #7 · answered by Philo 7 · 0⤊ 2⤋
the lowest is 3
12 = 3*2*2
15 = 3*5
21 = 3*7
2007-11-04 16:57:20 · answer #8 · answered by Ms. Exxclusive 5 · 0⤊ 3⤋
What common factor does each have?
Answer = 3
2007-11-04 16:55:47 · answer #9 · answered by kellenraid 6 · 0⤊ 3⤋
3. Smarten up.
2007-11-04 17:01:25 · answer #10 · answered by Shaun S 2 · 0⤊ 3⤋