Answer:
6/5t + 4/15s - 3
Explanation:
(-4/5t + 5/3s) + (-3 -7/5s + 2t)
You can only add like terms together so convert like terms to have the same denominator:
(-4/5t + 25/15s) + (-3 - 21/15s + 10/5t)
Get rid of the parentheses:
-4/5t + 25/15s - 3 - 21/15s + 10/5t
Combine like terms:
6/5t + 4/15s - 3