Question

how do you compare fractions and find the common denominater?

Answer 1

To find the least common denominator using this method, factor each of the denominators into primes. Then for each different prime number in all of the factorizations, do the following...

1.

Count the number of times each prime number appears in each of the factorizations.
2.

For each prime number, take the largest of these counts.
3.

Write down that prime number as many times as you counted for it in step #2.
4.

The least common denominator is the product of all the prime numbers written down.

Answer 2

Easiest way is to multiply the denominators together...This will get you a common denominator...It might not be the lowest common denominator, but it will be common

Example: 4/ 5 + 3 /4 =
4 / 5 ( 4 / 4) = 16/20 3 / 4 ( 5 / 5 ) = 15/20
16/20 + 15/20 = 31/20 = 1 11/20

Answer 3

so for 5, 6, 15 ...

5 = 1 * 5
6 = 2 * 3
15 = 3 * 5

one 2 * 3 * 5 ... gives you 30 ... which is the LCD .. least common denominator

Answer 4

another example ... try 9, 8, 12, 18 ...

Answer 5

15552 ... that is what you would get by multiplying all of em together ... nt to nice to handle, do you think? ... that'd be a reason to know the other method, too.

Answer 6

i mean you can reduce it down to 72 ... that's a difference and way easier to deal with.