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Addition or subtraction of fractions require "like" fractions: that is, fractions with the same denominator.

Q: Why do you have to find a common denominator?

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Pick two of the fractions and find the Least Common Multiple of those two denominators. Then take that number, and find the Least Common Multiple between that and the third denominator. This number will be the Least Common Denominator between the three fractions.If you don't care to find the Least common denominator, then just take the three denominators, and multiply them together.

The way that you can find the least common denominator is by first multiplying the 2 bottom numbers and whatever the product is that is your common denominator. to find the smallest one, you have to keep dividing it till it is in counting order or there is an odd number.

A common denominator is 7.A common denominator is 7.A common denominator is 7.A common denominator is 7.

You need to find the common denominator in order to add or subtract them. You can only add or subtract "like things" and by finding a common denominator you make both rational expressions into things that can be added or subtracted.

It's very difficult to find the greatest common denominator, mainly becausethere is no such thing.The one that people are always trying to find is the least common denominator.That means the smallest one, and that's the one you need to be learning howto find.

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When comparing fractions you must find a common denominator; by finding the least common denominator it will keep the numbers (numerators and denominator) smaller .

You Ned to find a larger common denominator or multiply the denominators to gain a common denominator.

You need at least two numbers to find a common denominator.

Many places, but a common one is in adding fractions where we find a common denominator.

You can always find a common denominator by multiplying the denominators together.

No.

To find a common denominator, it's what 4 and 7 go into, and that's 28.

You need at least two numbers to find something in common. 90 can be a common denominator of other numbers, but it can't have a common denominator all by itself.

For the sake of comparison, any common denominator will do.

The is no "largest" common denominator. For any denominator you find, we can multiply it by a natural number and come up with a larger one. Do you mean LEAST COMMON DENOMINATOR?