Answer:
Slope = -2.
Explanation:
The equation of given line is

We need to find the equation of line which is parallel to the given line.
If a line is defined as
, then

In the given equation a=2 and b=1, so the slope of given line is


The slope of given line is -2.
We know that the slope of two parallel lines are same.
Required line is parallel to the given line.
Therefore the slope of the line that is parallel to the line whose equation is 2x + y = 4 is -2.