\(\dfrac{x+y}{x-y}\cdot A=\dfrac{x^2+2xy+y^2}{3x+2}\)
\(\Rightarrow\dfrac{x+y}{x-y}\cdot A=\dfrac{\left(x+y\right)^2}{3x+2}\)
\(\Rightarrow A=\dfrac{\left(x+y\right)^2}{3x+2}:\dfrac{x+y}{x-y}\)
\(=\dfrac{\left(x+y\right)^2}{3x+2}\cdot\dfrac{x-y}{x+y}=\dfrac{x^2-y^2}{3x+2}\)