Answer:
7
Step-by-step explanation:

The solution depends on the value of

. To make things simple, assume

. The homogeneous part of the equation is

and has characteristic equation

which admits the characteristic solution

.
For the solution to the nonhomogeneous equation, a reasonable guess for the particular solution might be

. Then

So you have


This means


and so the general solution would be
There is no mode in these scores.
This is because mode is when two numbers show up the same like 4 and 4.