For each equation determines whether y is a funcation of x

All linear relations are functions
The quadratic equations can be a function if we restrict the domain of it
The given relations are
[tex]x=-9y[/tex]This is a linear relation, then it is a function, we can put it in the form
[tex]y=-\frac{1}{9}x[/tex][tex]y=8x[/tex]This is a linear relation, then it is a function
[tex]x+3y=6[/tex]This is a linear relation, then it is a function, we can put it in the form
[tex]y=\frac{6-x}{3}[/tex][tex]x=2y^2-3[/tex]We will put it in the form of y as a subject
[tex]y^2=\frac{x+3}{2}[/tex]To find y we will take square root for both sides
[tex]\begin{gathered} \sqrt[]{y^2}=\pm\sqrt[]{\frac{x+3}{2}} \\ y=\pm\sqrt[]{\frac{x+3}{2}} \end{gathered}[/tex]That means each value of x has 2 values of y, then
This can not be a function