First we have to convert the mixed numbers to fractions.
To do this multiply the denominator by the whole number.
10 x 1 = 10.
Then add the numerator.
10+17=27.
The fraction is 27/10.
Do the same for the other mixed number.
3 x 10 = 30
30+1=31. 31/10.
Now subtract.
31 27 14
__ _ __ = __
10 10 10
Then simplify: 1 2/5
Hope this helps!! :)