Question

Find the sum and please show work.
11/12-5/16+11/18
(These are all fractions by the way...)

Answer 1

Do you know what you need to do first?

Answer 2

Find common denominators?

Answer 3

Get them to all have the same denominator, 12*16*18=3456, then add or subtract and finally try to simplify the fraction you end up with.

Answer 4

Yes

Answer 5

Whatever you do to the denominator, you also have to do to the numerator

Answer 6

Okay, so what would be the common denominators for all of them?

Answer 7

douglas gave you a common denominator of 3456 by multiplying the numbers together

Answer 8

Then you would need to take the 3456 and divide by 12, 16 and 18 so that you know what to multiply the numerator by

Answer 9

I'm not sure that I understand... :(

Answer 10

If you take 3456/12 = 288

Answer 11

My final answer on wolframalpha.com was 1 31/144

Answer 12

So you would take 11 * 288 = 3168

Answer 13

4/12 becomes 20/60 by multiplying top and bottom by 5, for example

Answer 14

Your first equation is 3168/3456

Answer 15

First fraction

Answer 16

Correct on your 4/12

Answer 17

2nd fraction of 5/16

Answer 18

Could you please write this out for me? I do not understand, and I am more of a visual learner.

Answer 19

3456/16 = 216
216 * 5 = 1080
so your 2nd fraction would be 1080/3456

Answer 20

3rd fraction of 11/18
3456/18 = 192
192 * 11 = 2112/3456

Answer 21

So now lets put those all together

Answer 22

3168/3456 - 1080/3456+2112/3456

Answer 23

Now add (or subtract) the numerators

Answer 24

I'm lost, I'm sorry, I think I'll just skip this problem.

Answer 25

Thank you very much for your help anyways-I'll give you a medal for your awesomeness. :)

Answer 26

Do you understand how to get the common denominator?

Answer 27

I want you to understand it though... it will help you going forward

Answer 28

Yes, I understand the common denominator, I just don't understand combining them all at once...

Answer 29

When you have the common denominator, you have to figure out how many times the original denominator goes into that number, so that you can multiply the numerator by that number... each one by itself
\[\frac{ 11 }{ 12 }-\frac{ 5 }{ 16 }+\frac{ 11 }{ 18 }\]
Common Denominator = 12*16*18 = 3456
So on \[\frac{ 11 }{ 12 }\] \[\frac{ 3456 }{ 12 }=288\]Then you take the 11 (the numerator) and multiply it by 288
\[\frac{ 11*288 }{ 3456 }=\frac{ 3168 }{ 3456 }\]

Answer 30

Do you understand that part?

Answer 31

I don't understand the second step.

Answer 32

Okay... we determined that 3456 was a common denominator of all 3 numbers

Answer 33

So we know what our number is going to be for each of the fractions on the denominator, but remember we have to do the same thing to the numerator as we do for the denominator. The first fraction... in order to get 3456 on the bottom it would be 12*288 = 3456 (12 being the original number)... in order to get the 288, all I did was divide 3456 by 12

Answer 34

Thanks, but I have to go. I am going to look over this later and see if I can solve it. Thank you very much, you are amazing! :D

Answer 35

Okay... I'm attaching a file for you that might make it easier.

Answer 36

Nicely done.