System of differential equations depending on parameter This is the first time to get a question like this:
How to solve the system $y'=3by+(1-2b)z$, $z'=by+z+e^{4x}$, where $b\in\mathbb{R}$?
Any help is welcome.

Hint:
Substracting both differential equations gives us:
$$(y-z)'-2b(y-z)=-e^{4x}$$
This DE can easily be solved. It's a first linear DE.
