Add & Subtract Rationals – Common Denominator To add or subtract rational expressions with common denominators: 1) Add or subtract the numerators 2) Write the result over the common denominator 3) Simplify

Example 1 Add the numerators. Add the two rational expressions. Write the sum over the common denominator. Note that the denominators are common. Simplify

Example 2 Subtract the numerators. Subtract the two rational expressions. Write the difference over the common denominator. Note that the denominators are common.

Simplify

Example 3 Subtract the numerators. Subtract the two rational expressions. Write the difference over the common denominator. Note that the denominators are common. Important: the subtraction sign applies to the whole numerator!

Simplify the numerator Simplify the rational expression Note the sign change