If it's for a graph then I believe you just find the slope which you can do by taking two points and plugging them into this equation y-y
/
X-X
Example: (2, 4) and (6, 7) the first number is always x and the second is always y so if you plug those in the equation would look like this....
4-7
/
2-6
That would end up being
 3
- ---- aka the rate of change 
 4
P.s. The slash and the four dotted lines together means division. Hope this helps 
        
             
        
        
        
You just combine like terms
So 4d + - d = 3d
And 3x + 2x = 5x 
So the answer is 3d + 5x
        
                    
             
        
        
        
Answer:
Hmm. I'm not sure... But I just wanted to say I love your profile picture. 
Step-by-step explanation: