use the subspace theorem to decide if the sets is a real vector space with respect to the usual operation
the set of all solutions of the homogenous differential equation
7f''(x) +4f'(x) -6f(x) = 0
The Attempt at a Solution
try to put this second order d.e. into first order matrix system.
but don't know what to do next.
how to proof one matrix is under a vector space?