Answer:x=100
Step-by-step explanation:
Since you know that g(x)=3x-11 all you have to do is substitute that into g(x)=289. So you get 3x-11=289. To get x you have to add 11 on both sides.
3x-11=289
+11 +11
----------------
3x = 300
Divide 3 on both sides to get x by itself
3x =300
---- -------
3 3
x=100
the anser to that problem is -1/3
Answer: a = 
We want to isolate a. Add both sides by 2. Then we get u + 2 = 2a. To get just a, we can divide by 2 to get (u+2)/2.
Hope that helped,
-sirswagger21