Question

решить u/(u-v)-u/(u+v)

Answer 1

$frac{u(u+v)-u(u-v)}{(u-v)(u+v)} = frac{ u^{2}+uv- u^{2}+uv }{(u-v)(u+v)} = frac{2uv}{ u^{2}- v^{2} }$