Perpendiculat Line is when both slopes of equation multiplying each others and equal to -1.

For an easier way to understand, a perpendicular line has a negative reciprocal slope. For example if we are given the equation of y = 2x then the equation that is perpendicular to y = 2x would be y = (-1/2)x.
From both equations. We can either arrange in slope-intercepy form or use the slope formula which is m = -A/B when the equation is in Ax+By+C = 0 or Ax+By = C.

To find if these two lines are perpendicular to each others. Use the slope formula of -A/B.

Now recall that it is perpendicular when one of them is negative reciprocal of one another (-5/2 is negative reciprocal of -(-2/5) = 2/5 and 2/5 is negative reciprocal of -5/2).
Or in definition of perpendicular lines, both slopes multiply and must equal to -1.

Thus the equation is true which makes both lines perpendicular to each others.
Answer
- Both lines are perpendicular to each others.
Let me know if you have any doubts!