Adding and Subtracting Fractions - Algebra II

Convert each fraction to incorporate a common denominator. The least common denominator of 7 and 13 is 91. Multiply the first fraction by 13 divided by 13 and the second by 7 divided by 7 . Then add or subtract the resulting fractions.

Convert each fraction to incorporate a common denominator. The least common denominator of 9 and 7 is 63. Multiply the first fraction by 7 divided by 7 and the second by 9 divided by 9 . Then add or subtract the resulting fractions.

Convert each fraction to incorporate a common denominator. The least common denominator of 8 and 7 is 56. Multiply the first fraction by 7 divided by 7 and the second by 8 divided by 8 . Then add or subtract the resulting fractions.

Convert each fraction to incorporate a common denominator. The least common denominator of 6 and 5 is 30. Multiply the first fraction by 5 divided by 5 and the second by 6 divided by 6 . Then add or subtract the resulting fractions.

When adding fractions, the first thing we need to do is get a common denominator.

Then when adding, only add the numbers on the top, while leaving the common number on the bottom the same. Once we get a final answer, simplify accordingly.

Convert each fraction to incorporate a common denominator. The least common denominator of 3 and 8 is 24. Multiply the first fraction by 8 divided by 8 and the second by 3 divided by 3 . Then add or subtract the resulting fractions.

To be able to add the fractions, we will need to determine the least common denominator.

The least common denominator is since this is the minimal term that is both divisible by and itself.

Convert only the first fraction with the denominator of .

The answer is:

To subtract the fractions, we will need to find the least common denominator.

Write out the factors for both denominators.

Multiply four by 15 to get the least common denominator.

The least common denominator is .

Convert both fractions.

The answer is:

Find the least common denominator (LCD) and convert each fraction to the LCD and then add. Simplify as necessary.

The result is an improper fraction because the numerator is larger than the denominator and can be simplified and converted to a mix numeral.

Since the denominator is the same in both expressions, we can perform the subtraction in the numerator. The result will have the same denominator of 6x3y.

Simplify the expression:

Multiply all the nominators and the denominators separately.

Then, simplify the solution untill you get an answer that is an option on the exam.

An alternate, quicker solution would be to cancel out any matching denominators and nominators.

Once that is done, the equation simpifies to

To solve, we must first find a common denominator between 3, 4, and 12. All 3 numbers are factors of 12 and therefore 12 can be the common denominator. Then the numerators must be multiplied by the same factor as the demominator was.

This gives us our new fractions:

Next, we add the numerators, but our denominators stay the same:

.

Lastly, we simplify to get as our answer.

Determine the factors of both the numerator and the denominator:

We notice that 3 is a factor of both 12 and 39 so we can simplify by dividing both 12 and 39 by 3.

The result is therefore,

Start by making both fractions into the same denominator. One option is

Then adjust the numerators by multiplying each fraction's numerator by the other fraction's denominator:

Then add the adjusted numerators:

Then we simplify by dividing both numerator and denominator by 2:

which gives us the final result.

We start by adjusting both equations to the same denominator.

Notice that the denominator of the second term is a factor of the denominator of the first term. Therefore we only need to adjust the second term by multiplying both numerator and denominator by 2:

Now we need to subtract the numerators:

Convert the mixed number to an improper fraction.

Then add the numerators together and keep the common denominator.

Finally, simplify.

To add rational expressions, you must find the common denominator. In this case, it's .

Next, you must change the numerators to offset the new denominator.

becomes and becomes .

Now you can combine the numerators: .

Put that over the denomiator and see if you can simplify/factor further. In this case, you can't.

Therefore, your final answer is:

.

To subtract rational expressions, you must first find the common denominator, which in this case is . That means we only have to adjust the first fraction since the second fraction has that denominator already.

Therefore, the first fraction now looks like:

.

Now that the denominators are the same, combine numerators:

.

Now, put that over the denominator and see if you can simplify any further.

In this case, you can't, so your final answer is:
.

To add or subtract fractions, the fractions must have the same denominator.

The smallest common denominator in this case is .

After multiply both terms so that they have the same denominator.

Simply add these two terms together.