Adding fractions
When adding fractions, the denominator has to be the same.
In this problem, 
because the "b" and "d" were not the same, to come up with a common denominator, they had to be mulitiplied together, b(d)=bd. Whatever function is done to the denominator, has to be done to the numerator as well; this is why the "a" is multiplied by "d" and the "c" is mulitplied by "b".
because the "b" and "d" were not the same, to come up with a common denominator, they had to be mulitiplied together, b(d)=bd. Whatever function is done to the denominator, has to be done to the numerator as well; this is why the "a" is multiplied by "d" and the "c" is mulitplied by "b".Subtracting fractions
Subtracting fractions is much like adding them in that the denominators must be the same, so which ever function is done to the bottom, must also be done to the top. For this problem:
The common denominator is bd. Because the "d" is mulitplied by the denominator "b", it must also be mulitplied to the numerator "a", which then gives us the numerator "a(d)" or "ad". When the denominator "d" is mulitplied by the denominator "b", it is also mulitplied to teh numerator "c", which gives us "c(b)" or "cb". When put all together, it yields: ad-bc/bd.Mulitplying fractions
To multiply fractions, we first multiply the top and then we multiply the bottom, straight across. In this way, it is slightly different than when adding or subtracting fractions. As shown in this problem: 
Dividing fractions
When dividing fractions, we cross mulitply which means, the 1st numerator is multiplied by the second denominator. When this happens, the product becomes the new numerator. Next, the second numerator is multiplied by the first denominator, and this new product becomes the new denominator.
In this problem, the "a" is multiplied by the "d" an dthe "c" is mulitplied to the b, yielding a(d)/b(c).
You made it very easy to understand how "to do" fractions. From adding to dividing, it was a good lesson on how fractions work. I hated fractions growing up, so this made it easier to understand them with vidid detail and awesome explaination.
ReplyDeleteBe careful here, cross multiplication is a term we specifically use for equations, not division. We'll talk about this more when we get to fractions.
ReplyDeleteHere i am telling you The Fastest Way To Solve Fractions(Addition) Through Vedic Math, TRIX FOR THE SAT
ReplyDeleteTake these fractions for example
1/2 +1/3
how do u add them fast
well first we need to cross multiply
1*3=3
1*2=2
u get the numbers three and two now simply take the to answers and do the following
3+2
____
3*2
5/6
there u go u get the answer and u can use this for any addition of fractions
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hope this helps
**NICK**