Let y+1=Y and x+2=X
Such that dy=dY and dx=dX
Hence, we have: (XeYX+Y)dX=XdY
⇒XdY−YdXX2=eYXXdX
⇒e−YXd(YX)=dXX
⇒−e−YX=ln|X|+c
⇒−e−(y+1x+2)=ln|x+2|+c
∵(1,1) satisfy this equation
So, c=−e−23−ln3
Now y=−1−(x+2)ln(ln(∣∣∣3x+2∣∣∣)+e−23)
Domain:
ln∣∣∣3x+2∣∣∣>−e−23
⇒3|x+2|>e−e−23
⇒|x+2|<3ee−23
⇒−3ee−23−2<x<3ee−23−2
So, α+β=−4
⇒|α+β|=4