<span>x-y=2y -> x=3y and
3x-40+2y=180 --> 9y-40+2y=180 --> 11y=220 --> y=20, x=60 --> <A=<C=140 degrees, <B=<D=40 degrees.</span>
Given that <span>Jack rakes the yard in 5 hours and Jill rakes the yeard in 8 hours. Let the amount of time that it takes them to rake the yard together be t, then:
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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].
