Bonjour
Bronald20
[tex]\dfrac{1}{x-y}+\dfrac{1}{x+y}=\dfrac{x+y}{(x-y)(x+y)}+\dfrac{x-y}{(x+y)(x-y)}\\\\\\=\dfrac{(x+y)+(x-y)}{(x+y)(x-y)}\\\\\\=\dfrac{x+y+x-y}{(x+y)(x-y)}\\\\\\=\dfrac{2x}{(x+y)(x-y)}\\\\\\\Longrightarrow\boxed{\dfrac{1}{x-y}+\dfrac{1}{x+y}=\dfrac{2x}{(x+y)(x-y)}}[/tex]
