If you want to solve this expression think what is the multiples of 4? The lowest common multiples preferbaly to keep our number small. I came up with 8 and 4. So, this is my expression now: x/8-y/4=1/4 . Now you have to use trial and error. Think what numbers will I subtract to get 1/4. To find y you have to multiple your numerator and denominator by 2 to get 8, that is because the fractions rule says that denomiators must be the same when adding or subtracting fractions. I came up with 7/8-3/4=1/4. This is just one of the answers though there are multiple.