Differential equation solution

Hello,

I don't understand what the following question is asking - may I ask for someone to elaborate?:

"By considering the differential of z(x)=f(x)y(x), find the solution of the following differential equation:"

$\displaystyle (x^2+4)dy/dx + 2xy =0$ where $\displaystyle y(1) =5$

I've looked up solving differential equations, but most involve integration, which we have not touched on in lectures yet.

Or am I completely off track?

Thank you in advance for any feedback