Answer
a. neither
b. perpendicular
c. parallel
Work Step by Step
a. $x+y=5 \lt=\gt y=5-x$
$2x+y=5 \lt=\gt y=5-2x$
$-1\times2= -2$
b.$ 5y=2x-3 \lt=\gt y= \frac{2}{5}x-\frac{3}{5}$
$5x+2y=1 \lt=\gt 2y= 1-5x \lt=\gt y= \frac{1}{2}-\frac{5}{2}x$
$\frac{2}{5}\times-\frac{5}{2}= -1$
c. $y=2x+1 $
$4x-2y=8 \lt=\gt -2y=8-4x \lt=\gt y=-4+2x$