Answer:
So, solution of the differential equation is

Step-by-step explanation:
We have the given differential equation: y′′+4y=5xcos(2x)
We use the Method of Undetermined Coefficients.
We first solve the homogeneous differential equation y′′+4y=0.

It is a homogeneous solution:

Now, we finding a particular solution.

we get

So, solution of the differential equation is

Let plug the variable into the equation.


We can conclude that this is incorrect because

does NOT equal

The correct answer would be:

;

; or

or

All

of these are correct answers.
X=moira y=mother
x=1/2y-3
x=1/2(76)-3
x=38-3
x=35
Moira is 35 years old.
Oof. Sorry I can't help you there