What are the value of [math]x[/math] and [math]y[/math] in [math]\dfrac{x}{y}+\dfrac{x^2}{y^2}+\dfrac{x^3}{y^3}=14[/math] and [math]x+y=3[/math]?
If [math] \dfrac{x+1}{x-1}=\dfrac{a}{b} [/math] and [math]\dfrac{1-y}{1+y}=\dfrac{b}{a} [/math], then the value of [math] \dfrac{x-y}{1+xy}[/math] is?