First change 4/5 to 8/10 so that the fractions have the same denominator.
Now, add the whole numbers together: 13+4=17.
Now add the fractions: 8 tenths + 7 tenths = 15 tenths or 15/10, which cancels down = (5*3)/(5*2)=3/2, an improper fraction, which is 1 1/2. Add in the whole number part: 17+1=18 so the answer is 18 1/2.