# Algebra II : Adding and Subtracting Fractions

## Example Questions

### Example Question #81 : Adding And Subtracting Fractions

Explanation:

In order to add the fractions, change the denominator of the first fraction so that both denominators are common.

Simplify the fractions.

### Example Question #82 : Adding And Subtracting Fractions

Subtract the fractions:

Explanation:

Identify the least common denominator.  Write out the factors for the denominators.

The least common denominator is 18.  Convert all fractions to this denominator.

Since the denominators are common, we can subtract the numerators.

### Example Question #83 : Adding And Subtracting Fractions

Explanation:

In order to add the numerators of the fractions, we will need the least common denominator.

Multiply the denominators together.

Convert all fractions with this denominator.

Simplify the numerators.

### Example Question #84 : Adding And Subtracting Fractions

Subtract the fractions:

Explanation:

In order to subtract these fractions, we will need to determine the least common denominator, or LCD.

By visualization, the LCD is 36 because this is the smallest number that is divisible by both denominators.

Convert both fractions.

Subtract the numerators.  The denominators will remain the same.

### Example Question #85 : Adding And Subtracting Fractions

Explanation:

To convert the denominators, we will need to determine the least common denominator.  Write out some factors for each denominator.

The common denominator is .  Convert all fractions to this denominator.

Now that the denominators are common, add the numerators.

### Example Question #86 : Adding And Subtracting Fractions

Explanation:

First, identify the common denominator. In this case, it's 28. Now, offset the fractions to get the common denominator:

Combine the numerators:

Put that over the denominator:

### Example Question #87 : Adding And Subtracting Fractions

Explanation:

Determine the least common denominator by writing some of the factors of each denominator.

Convert the fractions to a denominator of 54.

Rewrite the fractions.

### Example Question #88 : Adding And Subtracting Fractions

Subtract the fractions:

Explanation:

Both fractions have unlike denominators.  To determine the least common denominator, multiply both denominators together and convert the fractions.

Simplify the fractions.

### Example Question #89 : Adding And Subtracting Fractions

Explanation:

Convert both fractions to a common denominator.

Multiply the top and bottom of the first fraction by two, and the top and bottom of the second fraction by eleven, which will provide the least common denominator.

Reduce the fractions.