Adding & Subtracting Rational Expressions
Rational expressions with like denominators are added or subtracted in the same way as number fractions with like denominators.
Step 1 Add or subtract the numerators.
Step 2 Write the sum or difference over the common denominator.
You can use this same method to add or subtract rational expressions with like denominators. Recall that in rational expressions, both the numerator and denominator can have variables.
Rule 1: To add two or more rational expressions having the same denominators we follow the steps:
Step 1: Add all the numerators
Step 2: Write the common denominator once.
Step 3: Simplify the rational expression obtained if possible.
Rule 2: Use the following steps to add or subtract rational expressions with unlike denominators.
Step 1: Find the LCD.
Step 2: Change each rational expression into an equivalent expression using the LCD.
Step 3: Add or subtract as with rational expressions with like denominators.
Step 4: Simplify if necessary.
Find out more about adding and subtracting rational expressions below.
Adding & Subtracting Rational Expressions
Practice: Add and subtract rational expressions with like denominators in the following exercises.