to solve this you need to find a common denominator
If you take the least common factor of 5 and 2 you can get the least common denominator.
This means that you find the smallest number that both 5 and 2 go into evenly
since 2 does not go evenly into 5 the next option is to try 10 (5x2)
both 5 and 10 do go evenly into 10 so that is our common denominator
Now you need to multiply both the top and bottom of the fraction by whatever number give you 10 in the bottom
5 times 2 is 10, 4 times 2 is 8
8/10
2 times 5 is 10
1 times 5 is 5
5/10
so you have 8/10 - 5/10
then just subtract the top number and leave the bottom as is
8 minus 5 is 3
3/10