Question

How do you add `\frac { 2} { 3} + \frac { 9} { 12}`?

Answer 1

Find a common denominator so that the factions will have the same denominator so that they can be added.

Explanation:

To find a common denominator find the factors of each number and multiply all unique factors to find the Least Common Denominator

`3 = 3 xx 1`
`12 = 2 xx 2 xx 3`

There is need for only one 3 as the factor of 3 is repeated.
There are 2 factors of 2 so The Least Common Denominator is

`2 xx 2 xx 3 =12`

Now change the fraction 2/3 to a fraction with 12 denominator.

`( 4 xx 2)/( 4 xx 3) = 8/12`

Now add `8/12 + 9/12`

`8/12 + 9/12 = 17/12`

`17/12 = 1 5/12`