Solving dy/dx = y+x: General Equation & Substitution Method

[thereddevils]

Homework Statement

Find the general equation of differential equation dy/dx=y+x

Homework Equations

The Attempt at a Solution

I don see a way to separate the variables. What substitution should i use?

 

[Office_Shredder]

I only see three possible choices for a function in your equation: x, y, or x+y

 

[thereddevils]

I only see three possible choices for a function in your equation: x, y, or x+y

sorry but i don get what u meant

 

[Dick]

sorry but i don get what u meant

I think Office_Shredder means you should look at the equation and take a guess at what might be a good substitution. What might work?

 

[hunt_mat]

Failing that, you could try an integrating factor of e^{-x}

 

[HallsofIvy]

I only see three possible choices for a function in your equation: x, y, or x+y

sorry but i don get what u meant

You said you were looking for a substitution! It wouldn't do much good to let u= x or u= y, would it? So what if u= x+ y?

 

[LCKurtz]

Homework Statement

Find the general equation of differential equation dy/dx=y+x

Homework Equations

The Attempt at a Solution

I don see a way to separate the variables. What substitution should i use?

Substitution?? Have you studied linear equations or constant coefficient equations yet?