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you don't need a CD for multiplication. only division.

you do need a common denominator duhhh

* * * * *

No, you do not need a common denominator for multiplication or division. But you do need it for addition or sutraction.
no you do not. You don't need one in division either. A common denom is only used in addition and subtraction.

a equation for multiplying would be

A a A*a

-- * -- = -----

B b B*b

Dividing is similar, just multiply by the inverse.

A a A*b

-- / -- = -----

B b B*a

Adding and subtracting are a little more complicated. Here is a formula to make finding the common denominator easy.

A a (A*b)+(a*B)

-- + -- = ---------------

B b B*b

A a (A*b)-(a*B)

-- - -- = ---------------

B b B*b

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Q: When multiplying fractions do you have to have a common denominator?
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Related questions

Do you need a common denominator multiplying fractions?

No.


When you are multiplying fractions do you find the common denominator?

no


Do you need a common denominator for dividing and multiplying fractions?

No you do not.


When multiplying fractions when they have same common denominator do you multiply the denominators?

YES.


Why don't you have to find a common denominator when multiplying fractions?

Multiplying fractions is quite different from adding them. You just multiply the numberators and the denominators separately. You can find the common denominator if you like, but in the end (after simplifying), you'll get the same result, and the additional work of finding the common denominator and converting the fractions turns out to be unnecessary. Try it out for some fractions!


Why is there no common denominator when multiplying or dividing fractions?

Because it is not how multiplication or division are defined.


Do you have to find the common denominator when you are multiplying fractions?

no. you can multiply straight across in fraction multiplication


How to change dissimilar fractions to similar fractions?

Note: numerator is the top part of the fraction, denominator is the bottom part. 1) Find a common denominator. It may be the least common denominator, but it need not be; just multiplying the denominators also gives you a common denominator, not necessarily the smallest one. 2) Convert each fraction so that it has this common denominator. This means multiplying numerator and denominator by the same number.


Do you have to have a common denominator when your multiplying?

no u dnt need to have a common denominator.. Just multiply both the denominator and numerator of the fractions u are working on and u will arrive at the answers


How do you find common denominators with dividing fractions?

When you're dividing fractions ... or multiplying thrm ... they don't need to have the same denominator.


How do you solve all fractions problems?

You basically have to learn separately how to do different things with fractions, including finding a common denominator; converting fractions to a different denominator; simplifying fractions; adding and subtracting fractions; multiplying fractions; dividing fractions.


Why does cross multiplying with fractions work?

When cross multiplying, finding the product of the means and extremes, you are technically getting a common denominator that reduces out.