9-4=-5 would be the smallest answer
Answer:

Step-by-step explanation:
It is a linear homogeneous differential equation with constant coefficients:
y" + 4y = 0
Its characteristic equation:
r^2+4=0
r1=2i
r2=-2i
We use these roots in order to find the general solution:

It is the third equation: −512⋅(65⋅13)⋅92=(−512⋅65)⋅(13⋅92)
Associative property means one can group the individual operations arbitrarily without changing the result.