Question

y=2x+5:(8, ),(-1, ),( , -1)

ordered pair

Answer 1

Just plug your numbers in and solve for the equation. In an ordered pair, the first number is x and the second number is y.
Put your 8 in place of the x and solve
y=2(8)+5, so y=16+5, so y=21
For the second one, do the same thing, putting -1 in the place of the x.
The third one is a little different because you are given y.
-1=2x+5 subtract 5 from each side to get
-6=2x. I think you know what to do from here. Good luck!