definiton of least common denominator?

Answer 1

...its the lowest possible common denominator between two fractions. Its pretty self-explanatory.

For example, if we want to evaluate:

1/3 + 7/9

in our heads, it would be easiest to find the least common denominator (LCD) of the two fractions first, which would be 9, and because 9 divided by 3 is 3, we will multiply the first fraction by 3.

(1/3 * 3/3) = 3/9, so:

3/9 + 7/9 = 10/9

I know this is kinda hard to catch, but i explained the best I could

Answer 2

okay-basic fractions-when u have 2 fractions with differing denominators it is the lowest possible number that both will divide into evenly
for example: you have 1/3 and 1/5-lowest common denominator is 15 because that is the lowest# both 3 and 5 will divide into evenly-further example
1/3 + 1/5=? 1/3=5/15 1/5=3/15 answer-8/15
get it?
if not, another example just in case
1/8 + 1/10=? lowest common denominator is 40 so 1/8= 5/40 1/10=4/40 answer is 9/40