A rational number for that question could be 5
Answer:
The equation is

and the graph looks like this
Answer:
A
Step-by-step explanation:
1.) 1+10a-5a
Subtract 5a from 10a
Final Answer: 1+5a
3.) x-9-3x
Subtract 3x from x
Final Answer: -9-2x
5.) 1-4n+2n-1
Subtract 1 from 1
-4n+2n
Add
Final Answer: -2n
7.) 10k-3k
Subtract
Final Answer: 7k
9.) 5r+4-4
Subtract
Final Answer: 5r