subtracting fractions?

Question

can some one help me with this problem

Answer 1

Give you an example...
Let's say we want to find the answer of 4/5 - 7/9
We have two fractions, OK, but we can not do anything with it because the first fraction has a denominator of 5, the second fraction has denominator of 9.
We need common denominator in order to do additions and subtractions of fractions.
Multiply the first fraction by 9/9 and the second fraction by 5/5,
now the expression becomes 36/45 - 35/45, now they share the common denominator!
The next step is very easy, simply do the arithmetic of the numerator and you will get the answer as 1/45

Answer 2

You must find a common denominator, that is having the same denominator and then subtract them.

example: 7/8- 2/5=
You find out that 40 is your least common denominator

7/8 You know that 8 goes into 30 6 times so you make the numerator and denominator 5/5 and multiply 5/5 and 7/8.

7/8 * 5/5=35/40

You know that 5 goes into 40 8 times and you multiply 8/8 and 2/5 together 2/5 * 8/8= 16/40

Subtract the like fractions 35/40- 16/40= 19/40

Answer 3

you need to make sure you have the same demoninator in both before you can subtract them.

example:

5/6 - 2/3

your denominators don't match, so you have to make them match. Here's how you do it.....

5/6 - 2(2/3)
5/6- 4/6
5/6-4/6 = 1/6

sometimes you have to multiply both fractions to get to a common denominator.

5/6-3/8

in this case, the least common denominator would be 24.

4(5/6)- 4(3/8)

20/24- 12/24

the answer would be 8/24, which reduces to 1/3.

hope this helped!

Answer 4

You have to have common denominators