Answer:
 and 20.5x
 and 20.5x
 
 and 6.2y
 and 6.2y 
Explanation:
 -3-x/5+6.2y+20.5x-3/8y

We are given an expression with 5 terms
The terms that has same variables with same exponent are like terms. WE combine only like terms. Constants are also like terms.
In the given expression , the fractions 
 and 20.5x have same 'x' . so they are like terms. we can combine these terms.
 and 20.5x have same 'x' . so they are like terms. we can combine these terms.
the fractions 
 and 6.2y have same 'y' . so they are like terms. we can combine these terms.
 and 6.2y have same 'y' . so they are like terms. we can combine these terms.