10,000 tiles * 0.25 = 2500
3000 -2500 = 500
so the delivery fee is 500 and the tiles cost 0.25 each
so the equation would be y = 0.25x +500
Answer is C
First look for the fundamental solutions by solving the homogeneous version of the ODE:

The characteristic equation is

with roots
and
, giving the two solutions
and
.
For the non-homogeneous version, you can exploit the superposition principle and consider one term from the right side at a time.

Assume the ansatz solution,



(You could include a constant term <em>f</em> here, but it would get absorbed by the first solution
anyway.)
Substitute these into the ODE:




is already accounted for, so assume an ansatz of the form



Substitute into the ODE:





Assume an ansatz solution



Substitute into the ODE:



So, the general solution of the original ODE is

Bearing in mind that an absolute value expression is in effect a
piece-wise function with two cases, thus