Adding and Subtracting Rational Expressions

1. In order to add or subtract fractions, they must have a common denominator

2. The lowest common denominator is the smallest number that is a multiple of all of the denominators

3. Once the lowest common denominator is found, rewrite all of the fractions as equivalent fractions with that denominator

4. Then add (or subtract) numerators, and keep the common denominator

1. if the denominators of the expressions you are trying to add are the same, simply add the numerators and keep the common denominator

Simplify the numerator by combining like terms

Factor the numerator and denominator to see if the expression can be reduced

1. Before you can combine rational expressions, they must have a common denominator

2. Check to see if the smaller denominator is a factor of the larger denominator

3. If one denominator appears as a factor in another denominator, you don't have to repeat that expression in the common denominator

4. The lowest common denominator must contain factors that appear in all the denominators

5. Once you have decided upon the common denominator, rewrite each expression as an equivalent fraction with the new denominator

6. Simplify by combining like terms in the numerator

7. Factor the numerator and denominator

8. Reduce by canceling like terms.