Answer
a. They are parallel lines.
b. The system does not have a solution.
Work Step by Step
a. $2x + y = 0$ and $y = -2x + 1$ are parallel lines.
We can put the second line equation in standard form ($Ax+By=C$) as the first one:
$2x+y = 1$. Their slopes are calculated as $m=-\frac{A}{B}=-\frac{2}{1}=-2$.
Since they have the same slope, they are parallel lines.
b. Since, they do not intersect, the system does not have a solution.