Question

2/3, 3/7, 7/8 common denominator?

Answer 1

ok, so a common denominator means "what number can I multiply all the bottom numbers by *something* to get the same number" - i.e. what are they common multiples of

Answer 2

correct

Answer 3

so one sure way to get a common denominator - a number all of the bottom numbers are divisors of - is to multiply them all together

Answer 4

so 168 is the common denominator.

Answer 5

yes, that is one common denominator for sure

Answer 6

since 168 is divisible by 3, 7, and 8 - and you know this is true since you multipled them all together

Answer 7

is that the lowest common denominator?

Answer 8

yes, I belive so: http://en.wikipedia.org/wiki/Least_common_multiple#Calculating_the_least_common_multiple

Answer 9

see the prime factorizatoin method part of that article

Answer 10

Thanks