Answer
If a line's equation is $y=mx+b$, then $m$ is its slope. Two lines are parallel if their slopes are equal.
Here: $2x+y=4\\x=-2x+4.$
Hence its slope is $-2$.
$4x+2y=0\\2x+y=0\\y=-2x.$
Thus its slope is also $-2$.
Their slopes are equal, therefore the statement is true.
Work Step by Step
If a line's equation is $y=mx+b$, then $m$ is its slope. Two lines are parallel if their slopes are equal.
Here: $2x+y=4\\x=-2x+4.$
Hence its slope is $-2$.
$4x+2y=0\\2x+y=0\\y=-2x.$
Thus its slope is also $-2$.
Their slopes are equal, therefore the statement is true.