Adding and Subtracting Fractions w/ Different Denominators?

Question

How do you add and subtract fractions w/ different denominators? I have a worksheet to do about it, and I have no clue on what to do. My parents don't either, and online it's too difficult, and my book is practically speaking a different language! Here's an example:
5/6+8/9
and
5/6-2/3
Please help me! I really need help on this.

Answer 1

Here's an easy way to add/subtract fractions.

Let's say you have
2/3 + 3/4

here are 3 easy steps:
1. multiply the numerator of the first addend to the denominator of the second addend.
2. multiply the numerator of the second addend to the denominator of the first addend.
3. multiply the denominators of the fractions. this immediately becomes the denominator of the sum/difference.

after doing the 3 steps, add the products of 1 and 2 and you'll get the numerator of the sum/difference.

Let's use 2/3 + 3/4 as an example
1. 2 * 4 = 8
2. 3 * 3 = 9
3. 3 * 4 = 12

therefore, 2/3 + 3/4 = (8 + 9)/12 = 17/12

now, what if you have 2/3 - 3/4?

you can still use the steps I provided

here's an example:
2/3 - 3/4 = 2/3 + (-3/4) (in the world of math, there is no such operation as subtraction. it's simply adding negative numbers)

1. 2 * 4 = 8
2. (-3) * 3 = -9
3. 3 * 4 = 12

therefore, 2/3 - 3/4 = (8 - 9)/12 = -1/12

i hope you understand.

Answer 2

The first thing to do is find a common denominator.

In the first example it's 18. Then convert the fractions. The first example would be 15/18 + 16/18. Then you add the numerators and you get 31/18. Then simplify the fraction to 1 13/18.

The second example would be 6 as a common denominator. Convert to 5/6 - 4/6. Then subtract the numerators: 1/6

Answer 3

If you have to add or subtract fractions with different denominators, then all you have to do is find a common denominator. For example, if you have to do 5/6+3/9 then you would find that 9x2 is 18, and 6x3 is 18. so then you multiply the numerator by the same number as the denominator. so 3/9 becomes (3x2)/(9x2) which is 6 over 18. Then you would go to 5/6 which becomes (5x3)/(6x3). That is then 15/18. then you just add the numerators and keep the denominator. Also, if you are still having trouble, you could always ask your math teacher.

Answer 4

all you have to do is find common denominators and the add

5/6+8/9 6 and 9s common denominator is 18 so multiply each fraction by the number that will turn the denominator into 18 in this case so the answer would be 31/18 and u cant simplify cuz 31 is prime

Answer 5

5/6 +8/9= 5/6=10/18 + 8/9=16/18= 26/18=1 8/18=1 4/9

factor out both of the denominators
6=2*3
9=3*3
2*3*3=18


5/6-2/3
do the same as in adding
6=2*3
3=3
2*3=6
5/6- 2/3=4/6= 1/6

Answer 6

you have to multiply each fraction by the common denominator and then add once multiplied...for example the common denominator for number one is 18, so you multiply 5/6 by three and 8/9 by two...

ex 1: 5/6+8/9= (3/3)*(5/6)+(2/2)*(8/9)=15/18+16/18=31/18
reduce if possible...its not

ex 2: (1/1)*(5/6)-(2/2)*(2/3)=5/6-4/6=1/6

Answer 7

5_
6
Write them in a ^ style.
Then find a number that both bottom
numbers are equally dividable into. Like with 6 & 9, 18 would work. Then multply the upper number times the amount you had to increase the bottom number. Then add or subtract the upper numbers, as required. IF you answer is on the large size like 12/24 you may want to condence it to 1/2.

Answer 8

Y!A isn't for 3rd graders. we're not babysitters. go do your homework shona where you belong!