Using signals and Equations

[DaSh]

Hi,
I have an equation like this: y'=Q-3y, when Q is a signal comming from Analog Input or simulated but not convencional, such as square pulses with dampings.
My question is which equation VI do I need to use in Labview that will use this signal "Q" as input parameter and perform the equation y'?
Thanks

[Labviewguru]

Can't you just use the multiply and subtract nodes?

What is "y"?

[DaSh]

Hi, y' is just a mathematic parameter from the equation. I just put a simply equeation to demostrate what I ment, but its usually more complex such as y'=Q-5y-6t-t'. Not always is the same equeation using n-parameters and their derivative. I just thought to use ODE equation or any other mathematic vi, but I didn't know how to give a signal as input parameter. However, the operator vis can be a simple solution.