For this case we have the following line equations:

We manipulate the equations algebraically until we write them in the slope-intersection form,

Equation 1:

Equation 2:

By definition we have:
If two lines are parallel then their slopes are equal.
If two lines are perpendicular then the product of their slopes is -1.
It is noted that the slopes are not equal. We check if the product is -1:

Thus, the lines are perpendicular.
Answer:
The lines are perpendicular