Answer:
B, E
Explanation:
There are a few ways to check for common denominator.
Here is one method
Take the 4 and 10 and see if both numbers will go into the numbers evenly. If they do, it is a common denominator
Will 4 and 10 divide evenly into 10 ?
4 will not go into 10 evenly
10 is not a common denominator.
Will 4 and 10 divide evenly into 20?
4 will go into 20 evenly. 20 /4 = 5
10 will go into 20 evenly 20 / 10 = 2
So 20 is a common denominator
Will 4 and 10 divide evenly into 24?
4 will go into 24 evenly 24 / 4 = 6
10 will not go into 24 evenly
24 is not a common denominator
Will 4 and 10 divide evenly into 32?
4 will go into 32 evenly 32 / 4 = 8
10 will not go into 32 evenly
32 is not a common denominator
Will 4 and 10 divide evenly into 40?
4 will go into 40 evenly 40/4 = 10
10 will go into 40 evenly 40 / 10 = 4
40 is a common denominator