Okay, so to subtract fractions, the numbers need to have common denominators. So you'd have to make 6 have a denominator of 10.
And how would we do this? Well, since six is a whole number, it's also 6/1. To make this fraction have a denominator of 10, we multiply both the numerator and denominator by ten, thus getting 60/10.
Next, you make 2 9/10 into an improper fraction. You should times two by ten, then add what you get to the numerator, thus getting an improper fraction of 29/10.
And then we just subract the numerators and keep the denominators, getting 31/10. To change this into a mixed number, just figure out how many tens can go into 31-- essentially, 31 divided by 10. You would get 3 remainder 1, so your mixed number is 3 1/10.
