To be blunt, it looks like you just copy/pasted a wall of text from whatever you're working on. Ask an actual question, and format the wall of text so that we don't have to decipher it ourselves. Don't expect people to help solve a problem like that if it looks like you gave no thought in posting it
The answer is 100 if you do it step-by-step
The range is -infinity to infinity
We have an equation: (5+b)/2= 5
⇒ 5+b= 5*2
⇒ 5+b= 10
⇒ b= 10-5
⇒ b= 5
Final answer: b=5~
