Answer/Discussion to 1a

y = 2x - 1

Since we can write it in the standard form, Ax + By = C, then we have a linear equation. 

(return to problem 1a)

If we add x squared to both sides we would end up with .   Is this a linear equation?  Note how we have an x squared as opposed to x to the one power. 

It looks like we cannot write it in the form Ax + By = C, because the x has to be to the one power, not squared.  So this is not a linear equation. 

(return to problem 1b)

Answer/Discussion to 2a

 y = 2x - 1

The three x values I'm going to use are -1, 0, and 1.  (Note that you can pick ANY three x values that you want.  You do not have to use the values that I picked.) You want to keep it as simple as possible.  The following is the chart I ended up with after plugging in the values I mentioned for x.
 
 

(return to problem 2a)

The three x values I'm going to use are -1, 0, and 1.  (Note that you can pick ANY three x values that you want.  You do not have to use the values that I picked.) You want to keep it as simple as possible.  The following is the chart I ended up with after plugging in the values I mentioned for x.
 
 

(return to problem 2b)