Diff Eq

[warped charm]

Looking for insight on why 4 is mult by 3 in this diff eq. Its a constant so wouldnt dy/dx = -3y ? Its wrong but I wanna see why Im wrong

[coral shard]

$\frac{dy}{dx}$ is $-3C_1e^{-3x}$

That is $-3[C_1e^{-3x}] -12 + 12$

$-3[C_1e^{-3x} + 4] + 12$

$-3y + 12$

[rose harbor]

kanny