Hello!
Okay, so first we need to add like terms... so first, add the terms with the same variables. That gives us:
9x + 7y + 4 + y
Now add 7y and y
That gives us:
9x + 8y + 4
This can't be added anymore... this is as far as we can go because they are no longer like terms.
<span>x = -2.375 Hopefully that helps :)</span>
the construction of fields of formal infinite series in several variables, generalizing the classical notion of formal Laurent series in one variable. Our discussion addresses the field operations for these series (addition, multiplication, and division), the composition, and includes an implicit function theorem.
(PDF) Formal Laurent series in several variables. Available from: https://www.researchgate.net/publication/259130653_Formal_Laurent_series_in_several_variables [accessed Oct 08 2018].