Please answer the following Question (35 Points)

Answer:
[tex]2r-2s[/tex]
Step-by-step explanation:
Start by removing the parentheses:
[tex](r-s)-(s-t)-(t-r)\\r-s-(s)-(-t)-t-(-r)[/tex]
Note that two negatives make a positive.
[tex]r-s-s+t-t+r[/tex]
Combine like terms
[tex]r+r-s-s+t-t\\2r-2s[/tex]