Adding and Subtracting Fractions with Unlike Denominators

No, it is only necessary to simplify the answer if you did not use the least common denominator.

To add fractions with unlike denominators, you first need to get common denominators by multiplying the two denominators. Then you can add the numerators.

A quick way to find the common denominator is to multiply the two denominators.

After finding the common denominator, you can add the numerators of the fractions.

Subtracting fractions with unlike denominators follows the same process as addition: find a common denominator and then subtract the numerators.

To simplify a fraction, divide both the numerator and the denominator by their greatest common divisor.

The least common denominator (LCD) is the smallest number that both denominators can divide into evenly.

Using the least common denominator means you won't have to simplify your final answer.

If you don't use the least common denominator, you may have to simplify your final answer.

For example, to add 1/7 and 2/3, you would multiply 7 and 3 to get a common denominator of 21.

The result is 13/21.

To subtract 5/8 and 3/7, you would multiply 8 and 7 to get a common denominator of 56.

The result is 11/56.

No, it is only necessary to simplify the answer if you did not use the least common denominator.

To add fractions with unlike denominators, you first need to get common denominators by multiplying the two denominators. Then you can add the numerators.