Answer:
Common denominator = 20
New fractions are: 
Step-by-step explanation:
Given:
The fractions are given as:

The denominators of the first fraction is 4 and that of the second fraction is 5.
In order to find the common denominator for 4 and 5, we have to find the least common multiple of each of the numbers.
Multiples of 4 = 4, 8, 12, 16, <u>20</u>, 24, 28,....
Multiples of 5 = 5, 10, 15, <u>20</u>, 25, 30,....
Therefore, the least common multiple of 4 and 5 is 20. So, the common denominator is 20.
Now, multiply the numerator and denominator of each fraction by the same suitable number such that the denominator becomes 20.
So, for the first fraction, 4 is in the denominator.
So, 4 when multiplied by 5 gives 20.
So, we multiply the numerator and denominator of first fraction by 5. This gives,

Now, for the second fraction, 5 is in the denominator.
So, 5 when multiplied by 4 gives 20.
So, we multiply the numerator and denominator of first fraction by 4. This gives,

Therefore, the new fractions after making the denominators same are:
