Example of subtracting fractions with unlike denominators

If you conquered adding fractions with different denominators, then subtracting fractions will be a snap. Don't worry...we'll take it slow and explain every step.

Example of subtracting fractions with unlike denominators

Discussion and questions for this video
u have to do that in order to answer the question.If u dont find the LCD or the common denominator then ur answer would be wrong
Why do you have to make the denominators the same? Can't you just subtract the numerators and the denominators?
Don't worry, eventually you'll get the answer, and you'll feel so great because you're so smart! Don't feel down because math is hard, because if you try enough, you will get it and it will be the best thing in the world! Good luck! :D
But you forgot that you need to multiply 13 to 7 and 12 to 6 in order for the fraction to stay the same and not ruin the equation, that's why its 91-72 which is equals to 19. If its still vague i can give an example
I don't get the part at the end dividing it because on my sum I divided and I got an answer and now I have know idea what to do and I have to sign it in toady at 2 pm
Can you use the up and down way while subtracting fractions? 9
Also can you do it an easier way? + 8
For your 1st question, yes, and the 2nd one..well in my opinion long way is easier.
when adding or subtracting fractions, you need to have a like denominator, or the same denominator, because that way, the answer won't have a completely different denominator. example: 2/5-1/3
you shouldn't just leave the denominators the way they are and subtract them from each other, because then you will have the answer 1/2
Yes, just like 20/80 equals 1/4. When the numerator is 1, (like 1.2,) it cannot be simplified anymore. If, for example, 5/6 is your fraction you simplified, it cannot be simplified anymore either, because the numerator is one away from the denominator. I hope this helps!!
First of all, we would convert the mixed numbers to improper fractions:
11/4 - 73/10
Then we would find a like multiple of the denominators, 4 and 10, such as 20. 20/4 is 5, so we'd multiply the numerator and denominator by 5, to get 55/20. 20/10 is 2, so we'd multiply the numerator and denominator of 73/10 by 2, to get 146/20. Our final problem:
55/20 - 146/20 = -91/20
So what he did near the end was combine the two fractions into a fraction with a like denominator and the two different numerators that are being subtracted., because only numerators can be subtracted.
Sorry this is late but hope this helps
What if one of the numerators are equal to each and make zero what would happen then?
how do i find the comon denominator in 15/16 +1/6 please help me figure this out please i begging you
So all you have to do is multiply then subtract? Would that be mathmatically correct or still wrong?
example: 1/2-1/4=?
Explanation: do this
2X2=4 1X2=2
Easier way: 2/4-1/4
Hope i Helped you
That's really complicated. Is there by any chance an easier/simpler way to do this?
at 0:43 why did he put the dots as multiplication signs if there is no algebra?
It doesn't have to be algebra when you are using dots as multiplication signs. You can sue a dot as the sign anywhere in a multiplication problem, its just that most people use an x as the multiplication sign before they reach algebra.
can you please explain more because i don't get it at all. like how to divide
Oh it is easy. First take any fraction(9/13) and divide it by(3/4). All you need to do is take the reciprocal of the second no.(3/4)and multiply both of them. If you can simplify do it.

Hope this was helpful
how come when i was doing the question with him i got a repating dectimal
The way it compares cause it is all math and it is fractions just sith diffrend botton numbers
What if the numerator is lower than what you are subtracting by like 5/10 - 8/17? Please help!
Well, in this example you will need to find a common denominator. For simplicity we will use 170. So the problem you gave really comes out to 85/170 - 80/170. The answer becomes 5/170 or 1/34.
If you mean what happens when the fraction that you are subtracting by is lower than the other fraction, well, then you would have a negative answer.
And what if a fraction has a numerator bigger than the denominator. For example. 6/2 - 7/4?
Basically, you just need to make this problem that you don't know how to solve into one that you do know how to solve. You just need to make the denominators (the bottom numbers) the same.

EX: 1/2 - 2/4
STEP 1) We know that 2 is half of 4, so 2/4 is actually just 1/2.
STEP 2) 1/2 - 1/2 = 0

I hope this helps!
you have to make the denominators "like" before you can do anything else. you have to find the LCM (Lowest Common Multiple) which makes the denominators equal. hope this is of any help to you :)
How do you solve a fraction with one whole number and the other number another fraction Ex: 1 and 3/20- 9/10?
1 3/20 is same as 20/20 + 3/20 which makes 23/20, now substracting 9/10 can be by giving the same nominator, so 9/10 is same as 18/20, 23/20 - 18/20 = 5/20 = 1/4
If at an election 6/9 of the members voted and there are 171 members how many people actually voted? Not sure how to work this problem.
Shure be glad too say we need to subtract 1/2 -1/4 first we need to get them to the same denominator by multiplying the numerator and the denominator by 2 to get 2/4-1/4 which is now a very simple fraction problem.
Hope this helped.
and good luck.
well for thelove off pizza, of course you need to get the lowest common denominator, it says it in the title
How do you add and subtract positive and negative fractions with different denominators
why is it that big of a number, when ur just subtracting those little number... it's like your adding instead of subtracting!
Hello Hannah, if you find yourself frustrated or confused by a topic or what Sal says in the video, you may try either:

1) rewatching the video, pausing and repeating confusing parts
2) reading through the questions and answers in here (some might contain the little bit you're missing)
3) asking specific questions about what you don't understand

Good luck!
How do you figure out 4 cups of flour and you need to use 1 3/4 cups for a recipe. How much do you have left?
We can make that problem easier by estimating a bit to get the whole number portion of the question out of the way. We know you are using 1 whole cup and part of another, so lets round up to 2 cups being used and subtract them from the initial 4 cups, which means that we know for sure there are at least 2 whole cups remaining.

After taking those off the question is now how much is left of the remaining 2 cups if we take 1 3/4 cup away. We can subtract out that whole cup used from both values leaving us with 1 cup - 3/4 cup which is a much easier problem to figure out.

We then take the answer to that and add it back in with the other 2 whole cups we had already determined would be left over.
😲what happens if the denominator?do you need to add/subtract both of the denominator?😵
it is depend all on multiplication ,division,subtraction and addition