Answer: - 1.
Step-by-step explanation:
[tex]\frac{\dfrac{x+y}{x-y} }{\dfrac{y+x}{y-x} } =\dfrac{x+y}{x-y} \div \dfrac{y+x}{y-x}\\\\{\: \: \: \: \: \: \: \: \: \: \: \: \: } = \dfrac{x+y}{x-y} \times \dfrac{y-x}{y+x}\\\\{\: \: \: \: \: \: \: \: \: \: \: \: \: } = \dfrac{x+y}{x-y} \times \dfrac{-(x-y)}{x+y}\\\\{\: \: \: \: \: \: \: \: \: \: \: \: \: } = \dfrac{-(x+y)(x-y)}{(x-y)(x+y)} \\\\{\: \: \: \: \: \: \: \: \: \: \: \: \: } = -1[/tex]
