Answer:
8r + 14s - 7T
Explanation:
Hello!
We have to make sure the terms are like terms before we add them.
Like terms are terms with the same variable so we can add r's with r's, t's with t's, etc.
There are two r's and two s's so we can simplify those
12r - 4r = 8r
5s + 9s = 14s
Now put these all together with the T in the original equation to get the answer
8r + 14s - 7T
Hope this helps!