Two different subtraction problems that use only odd numbers for numerators and each have different of 3/4.

Step-by-step explanation:

We did a systematic search for subtraction problems of this type, eliminating ones that are too trivial, such as 1/1 - 1/4 and equivalents of those with integers added, such as 3/1 - 9/4. Even so, there are an infinite number of possibilities. some of the ones involving larger numbers in the range we looked at include ...

___

A reasonable approach to doing this by hand seems to be to choose a denominator for the minuend, then a denominator 4 times that value for the subtrahend. Express 3/4 using the latter denominator, and find two numbers that differ by that numerator, one of which is divisible by 4, but not by 8.

Example: Choose 13 as the minuend denominator. Then 52 is the subtrahend denominator, and the difference you need to create is 39/52. The smallest odd number we can add to 39 to make it divisible by 4 but not 8 is 5. So, we can use (39+5)/52 and 5/52 as our numbers that differ by 3/4. In reduced form, that subtraction is ...

  11/13 - 5/52

Note that if you choose an even denominator, then the exact procedure will vary depending on what power of 2 is a factor of the denominator.