00:01
Let's solve problem 10.
00:02
Calculate and express each result in its simplest form.
00:07
2 by 9 minus 5 by 6.
00:10
So in case of doing addition or subtraction, we have to know different type of fractions.
00:18
We have like like fractions and unlike fractions.
00:23
Like fractions are those who have same bottom number or denominators like b by a and c by a.
00:33
In case of like fractions to do the subtraction, we can simply keep the bottom number or the denominator and we will simply subtract the top numbers.
00:46
For b by a minus c by a, we will do b minus c by a.
00:53
But in case of unlike fractions like b by a and c by d, where the bottom numbers are different.
01:01
To do the addition or subtraction, we have to convert them into like fractions first.
01:08
So let's do it for our example.
01:11
We have 2 by 9 and 5 by 6.
01:16
So to make them like fractions, we will take the multiples of the bottom numbers or the denominators, like 1 into 9 is 9, 2 into 9 is 18 1 into 6 is 6 2 times 6 is 12 3 times 6 is 18 we will do the multiples until we get the same numbers like here we got 2 times 9 is 18 and 3 times 6 is 80 so this is called list common denominators or simply lcd...