Is my following statement true? Thanks. Given F(x1,x2,..,xi,..,xn)=constant, where F(.) is any function.

Then xi can be expressed as xi=G(x1,x2,..,xi-1,xi+1,..,xn), where G is also any function.

Is my following statement true? Thanks. Given F(x1,x2,..,xi,..,xn)=constant, where F(.) is any function.

Then xi can be expressed as xi=G(x1,x2,..,xi-1,xi+1,..,xn), where G is also any function.