Question

How are a common denominator and a common multiple alike and different?

Answer 1

The correct answer is:

Both common denominators and common multiples are found the same way, but a denominator is strictly on the bottom of a fraction while a multiple is not.

Explanation:

To find a common denominator of two fractions, you find a number that both denominators of the given fractions will divide into.

To find a common multiple of two numbers, you find a number that both given numbers will divide into.

This is the same process for both things. However, once you find the common denominator, you then write it in the denominator of a fraction. Once you find the common multiple, you're finished.

Answer 2

East common multiple is the smallest multiple both numbers can go into. (Example: the LCM of 10 and 4 is 20, because both 10 and 4 go into 20 and 20 is the smallest number both 10 and 4 can go into. You could just multiply them both, but you'd get 40 and since its a bigger number it would be harder to work with.)

Least common denominator is just the least common multiple as a denominator. (Example: if you wanted to find the LCD of 5/7 and 1/10, you'd have to find the LCM of the demoniators (7 and 10) and then just use that as the denominator when adding fractions with unlikely denominators.) Sorry for such a long answer :P