Question 646693
{{{f(x)=  -5y/x+7}}}..........hyperbolic paraboloid

{{{f(x)= (7x-5y)x}}}
or
{{{f(x)+5y/x= 7}}}

{{{f(x)= 7-5y/x}}}

{{{(d/d(x))(7-5y/x)=5y/x^2}}}



*[tex \LARGE \ \ \  \ \sum_{i=\pm\infty}\(7-5y/x)=7 ]


domain: 

*[tex \LARGE \ \ \ \ \ \ \ \ \ \ \text{domain}(f)\ =\ \left{x\,\in\,\mathbb{R}\,:\,x\,\neq\,\0,\\right}]


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ \text{range}(f)\ =\ \left{x\,\in\,\mathbb{R}\,:\,x\=,\pm\,\infty)\\right}]