hi, i need to know what this is

Attachment 12839

i know i need to change tham to a top heavey fraction but i don't know how to do it, please could you show me what to do with workings out!!

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- Sep 11th 2009, 06:33 AMandyboy179fraction hard!
hi, i need to know what this is

Attachment 12839

i know i need to change tham to a top heavey fraction but i don't know how to do it, please could you show me what to do with workings out!! - Sep 11th 2009, 06:42 AMFinley
The question isn't very clear in my opinion. Can you make it neater? :O

- Sep 11th 2009, 06:43 AMandyboy179
sorry i just saw that, it was ok while i was writing it, sorry again

- Sep 11th 2009, 06:54 AMFinley
Yes, it would be wise to convert these "mixed fractions" to "top heavy fractions" or "proper fractions" as they're otherwise called!

To do this, multiply the number in front of the fraction by the denominator and then add the numerator.

eg: $\displaystyle 4\frac{3}{2}$

**Step 1**: Multiply the number in front by the denominator (The number on the bottom of the fraction which happens to equal 2 in this example):

$\displaystyle 4*2=8$

**Step 2**: Add this number to the numerator of the fraction (The number on the top which happens to be 3 in this example):

$\displaystyle 8+3=11$

**Step 3**: Place this new number (11) over the original denominator (number at the bottom) which is 2:

$\displaystyle \frac{11}{2}$

Voila! There is a mixed fraction converted to a "top heavy fraction"

Try doing the question yourself following these steps! Otherwise, I'm happy to help further :) - Sep 11th 2009, 07:02 AMandyboy179
- Sep 11th 2009, 07:05 AMFinley
My post was merely an example, the answer didn't apply to your question!!

However, the first part of your answer is entirely correct!

$\displaystyle \frac{22}{7} - \frac{11}{5}$

However, we need to go a few steps further to get the final answer!!

Firstly, can you subtract two fractions that don't have a**common denominator?** - Sep 11th 2009, 07:08 AMandyboy179
- Sep 11th 2009, 07:17 AMFinley
No, the answer is not $\displaystyle \frac{11}{2}$

To simplify http://www.mathhelpforum.com/math-he...f0e30884-1.gif we need to find the**LOWEST COMMON DENOMINATOR**of the two fractions. In other words, we need the two**BOTTOM NUMBERS**of the fractions to be**THE SAME**.

The easiest way to find a COMMON DENOMINATOR is to multiply the two DENOMINATORS (bottom numbers) together:

Aka. $\displaystyle 7*5=CD$

Therefore Common Denominator = 35

Therefore,

$\displaystyle \frac{110}{35}-\frac{77}{35}$

What I've done is place the original numerators (22 and 11) over the COMMON DENOMINATOR. What we do to the bottom, we must do to the top (this keeps the ratio even).

In other words, to get from 7 (the denominator in the first fraction)) to 35 we needed to multiply it by 5! To get from 5 (the denominator in the second fraction) to 35 we needed to multiply it by 7!

**What we do to the bottom, we do to the top!!**

Keeping it short,

22*5 = 110 (New numerator for first fraction)

11*7 = 77

Now to simplify $\displaystyle \frac{110}{35}-\frac{77}{35}$!

**Deal with the numerators only:**

**110-77 = 33**

**Place the new numerator over the common denominator (35):**

**33/35**

33/35 Can't be simplified any further, hence this is the answer!

Answer: $\displaystyle \frac{33}{35}$ - Sep 11th 2009, 07:19 AMandyboy179
i just looked in my book on how to do it, i know what the answer is now!

it would be:

$\displaystyle \frac{33}{35}$ - Sep 11th 2009, 07:20 AMandyboy179
- Sep 11th 2009, 07:23 AMFinley
No problem!! Hopefully it's beginning to make more sense :) Grappling the logic behind fractions will help enormously in later mathematics.

:)