Question

What is a line through which two points would be perpendicular to the line `y=2/5x-5/2`?

Answer 1

There are infinitely many such lines. See explanation.

Explanation:

There are infinitely many lines perpendicular to a given line (here `y=2/5x-5/2`).

Any line in a form `y=-5/2x+c` is the solution to this question.

Without additional informations (like a point belonging to the perpendicular line) only such general answer is possible.