Question

how do you subtract fractions with different deonamters

Answer 1

yoou must make the denominaters the same.

Answer 2

Your profile picture mixed with your spelling of "deonamters" leads me to believe you are a troll. In the event that you're not...

You multiply both fractions' numerators and denominators by the denominator of the other you're adding or subtracting, i.e.:

a/b+c/d=(ad+cb)/bd

Answer 3

ok thanks so much

Answer 4

sorry is this the user loveyou? both of you use the same avatar so I was just curious

Answer 5

nope

Answer 6

It's a common picture on the internet. http://knowyourmeme.com/memes/awesome-face-epic-smiley

Answer 7

ok thanks sorry to bother you

Answer 8

oh no its ok

Answer 9

Would you like an example for subtracting fractions?

Answer 10

oh yes please

Answer 11

\[\frac{2}{5}-\frac{7}{3}\]
So pretend we want to simplify this

Answer 12

we need the denominators to need to be the same
do you know how to find the lcm of two numbers?

Answer 13

"Pretend" we want to simplify this? WE DO!

Answer 14

\[{a \over b} - {c\over d}\]
\[={ad \over bd}-{bc \over bd}\]
\[={ad-bc \over bd}\]

Answer 15

you multiply them right

Answer 16

well sometimes that gives you the lcm
and in this case it does :)
5(3)=15 right
so we want to write both of out fractions with the denominator 15
so we have...
\[\frac{2\cdot 3}{5\cdot 3}-\frac{7\cdot 5}{3 \cdot 5}\]

Answer 17

\[\frac{6}{15}-\frac{35}{15}\]
so now we have the same denominator

Answer 18

so we can now write this as
\[\frac{6-35}{15}\]

Answer 19

and 6-35=-29

so we have the answer is....
\[\frac{-29}{15}\]

Answer 20

ok thanks so much myininaya for taking all your time to that

Answer 21

now i get it

Answer 22

cool! :)

Answer 23

I'm tearing up... watching someone learn fraction addition. ಠ_ಠ

Answer 24

i am in 4th grd lol

Answer 25

oh thanks so much just got it i needed to learn because i got a test tomorrow so its useful to know thanks and bye