Parallel lines have the same slope. Perpendicular lines have negative reciprocal slopes.
Rewriting the 2nd equation to solve for y, You get:
Y=1/5x + 1/2
The first equation slope is negative, and the second is positive. However, the second slope is 1/5, and not 5/1 - which would be the negative reciprocal of (-1/5)from the first equation.
