A line in the plane can be described under one of 4 following forms: an
explicit function, an implicit equation, a pair of parametric equations, or
two points on the line. A situation that generalises over affine subspaces
of higher dimension (such as a line or a plane in the space).

This exercise can present on such subspace under one of the forms of the
description, and ask you to describe it under another form. With the
variation of dimension, it can be used either in very elementary levels
(line in the plane), or right up to situations requiring complicated computations
of linear algebra.

Note that the server does not give standard solutions, as the solutions are
in general not unique.