Start by adding the x values together. This is easy because they have the same denominator (5). 2/5+1/5= 3/5. This next part with the fractions without 'x' is fairly easy. If you recognize that 5/8 and -1/4 can be changed so that they have the same base. Multiply both the numerator and denominator of -1/4 by 2, which gives you -2/8. Then subtract this from 5/8 and then you get 3/8.