Answer:
k i am going to tell you what's wrong with all of them, then i will give you the right answer
For the first one they did not combine the variable correctly
the second one needs to use 180, not 90
the third one is not set up like the first one and is supposed to. (115+5x+10=180)
1) 21.5
2) 133
3) 11
Hope this helps!! Have a good day and remember to be tiger fierce!! :)