Question

What is the common denominator of 4/5 and 1/3?

Answer 1

15

Explanation:

You can find this by multiplying the two deniminator numbers. 3*5
Although this dosent always find the lowest deniminator when you are dealing with high numbers, but it will get you an deniminator.

Answer 2

see below

Explanation:

The common denominator of two fractions is when the denominator is the same for both fractions, and the numerator is adjusted to take account, so the respective fractions are equivalent.

You can have an infinite number of common denominators, but we usually use the LOWEST common denominator, which is the lcm of both denominators

In this case we have

`4/5, 1/3`

we need the`" " lcm(3,5)`

by listing out the multiples of the two numbers we can see that

`lcm(3,5)=15`

This is left for the reader as an exercise to check

`4/5-= ?/15`

to find the numerator we see that having multiplied `5" by " 3" "`in the denominator we need to do the same in the numerator

`4/5-= (4xx3)/15=12/15`

`:. 1/3-=5/15`

this being left as an exercise for the reader to verify