ADDITION & SUBTRACTION: RATIONAL EXPRESSIONS
Adding and subtracting rational algebraic expressions. Just like regular fractions, they need a common denominator!
Adding and subtracting rational expressions is similar to adding and subtracting fractions. If they have the same denominator, just add or subtract the numerators and copy the denominator. If they have different denominators, you must find the LCD to make them the same.
1. Same Denominator: ax + bx = a + bx
2. Different Denominators: Find the LCD. Multiply the numerator and denominator of each fraction by the necessary factor to make the denominators the same, then add or subtract.
Denominators are x and y. LCD is xy.
Multiply first fraction by y, second by x:
3yxy + 2xxy
Add numerators: 3y + 2xxy
Denominators are a and b. LCD is ab.
Multiply first fraction by b, second by a:
5bab + 4aab
Add numerators: 5b + 4aab
Denominators are m and n. LCD is mn.
Multiply first fraction by n, second by m:
7nmn + 2mmn
Add numerators: 7n + 2mmn
Denominators are p and q. LCD is pq.
Multiply first fraction by q, second by p:
qpq + 8ppq
Add numerators: q + 8ppq
Try It Yourself!
Answer all 3 guided questions. Hints and solutions are available if you need them!
Quick Quiz Time!
Answer all 10 questions in one go. Good luck!
Made for students who want to master Addition & Subtraction of Rational Algebraic Expressions