Question

If you wanted find the difference of 6/25 - 4/5 , what common denominator should you choose?and why?

Answer 1

Look at the multiples of 5: 5, 10, 15, 20, 25, 30

Which of those is also divisible by 25?

Answer 2

So 5 would be the common denominator?

Answer 3

No. 5 is not divisible by 25. The common denominator is 25.

4/5 = 20/25

25/5 = 5
5 * 4 = 20