# Can someone please explain how to solve this IVP?

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1. Oct 22, 2015

### marchingt9

• Missing homework template due to originally being posted in other forum
x' =-5x-y
y' =4x-y

I got
x=ae^-3t+bte^-3t
y=-2bte^-3t+2ae^-3t+be^-3t
a=0 b=0

x=e^(-3t+3)-te^(-3+3)
y=-e^(-3+t)+2te^(-3+3)
I dont understand where the +3 comes from

2. Oct 22, 2015

### Geofleur

What are the initial conditions on x and y?

3. Oct 24, 2015

### HallsofIvy

Staff Emeritus
$e^{-3t+ 3}= (e^3)e^{-3t}$. The "+ 3" just gives a specific value to your constant "a".

4. Oct 24, 2015

### Ray Vickson

This is not an IVP, because you have not given any initial values. That is what the "IV" stands for.