If you plug in the x and y values for the points (X,Y). 
Then you are able to solve for the equation by seeing whether or not it equals the Y value. 
Ex. Solving 9a. 
Step One Equation and Point (2,0) or (X,Y)
[tex]y =  ({x})^{2}  - 3(x) + 2[/tex]
Step 2 Plug in and solve 
[tex]0 =  {2}^{2}  - 3(2) + 2[/tex]
0=4-6+2
0=0
Done and Answer is Yes it does fit.