Answer:
This is so easy
Let me explain:
first lets find out (f+g)(x)=-x+3x+5+x^2+2x=
x^2+4x+5 this is the equation of a parabola because we have x^2
so only the first graph shows us a parabola 
which remains the right one.
 
        
             
        
        
        
I think the best answer is 3 to 9 but thats not a answer so 3 to 6
        
                    
             
        
        
        
D because they all increase by the same number (+1)
        
                    
             
        
        
        
The way you convert is by dividing your answer to the question by 1,2or how many they are talking about . Once you do that you will get your answer which may be a decimal and the you put the unit kg for kilograms. so that will be the answer to the problem.