The number is 21 because 2 is 1 doubled, and 2+1 is 3.
For a linear equation like this there will always be infinitely many solutions if you let x and y be any real number. So you can just pick any x and find the corresponding y. Take for exmaple x=1 then we get
-1+2y=8
2y=9
y=9/2=4.5 so an ordered pair that satifies your equation is (x,y)=(1,9/2).
Now you can go on and find more.
If the diameter is 18, the radius would be nine. Someone please tell me if I missed something.
Answer:
what graph
Step-by-step explanation:
