Answer:
so add the ones that are given and then subtract from 360 because they must total to 360. so 360-80-68-84-56-40=32 so A
Let's just start with x=20 and then do some algebra to it to make it all complicated
x = 20
2 * x = 2 * 20
2x = 40
2x - 13 = 40 - 13
2x - 13 = 27
What you do is you combine like terms... so in your instance it is using m.
9m+2= 3m-10
-3m -3m
3m + 2 =-10
+10 +10
3m= 12
m= 4
