How do i find the answer for 25/8-6/8

First, subtract the numerators and keep the denominator. so it will be 19/8 then turn into a mixed number which will be 16 1/4

So 2 and 5/8 equals 21/8. Whenever you turn a mixed number into an improper fraction, multiply the whole number by the denominator and add the numerator. Since both fractions already have a common denominator, all you need to do is subtract the numerators and don't touch the denominator. 

21/8 - 6/8 = 15/8 = 1 7/8

This cannot be simplified any further so I would write it as a mixed fraction. 

Hope this helps!