7. Addition and Subtraction of Fractions

Recall that to add or subtract fractions, we need to have the same denominator.

Example 1

Add the fractions: `2/3+4/15`

Solution: Here, the lowest common denominator which we can use is `15`. So we have:


Subtraction works in the same way, as we see in the next example.

Example 2


Example 3


Example 4


Continues below


Simplify the following.

(1) `2/(s^2)+3/s`

(2) `5+(1-x)/2-(3+x)/4`

(3) `5/(6y+3)-a/(8y+4)`


Search IntMath, blog and Forum

Online Algebra Solver

This algebra solver can solve a wide range of math problems.

Algebra Lessons on DVD


Easy to understand algebra lessons on DVD. See samples before you commit.

More info: Algebra videos

The IntMath Newsletter

Sign up for the free IntMath Newsletter. Get math study tips, information, news and updates each fortnight. Join thousands of satisfied students, teachers and parents!

Given name: * required

Family name:

email: * required

See the Interactive Mathematics spam guarantee.