Respuesta :

iciclepiano18

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]