Ready solution of the problem. The sorcerer of Arutyunov. Task number 258.

251 - 260. Find the smallest and largest values of the function z = f (x, y) in the closed domain D defined by the system of inequalities. Draw a drawing.

258. z = x2 + 2xy - y2 + 4x; X ≤ 0, y ≤ 0, x + y + 2 ≥ 0.

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Detailed solution. Decorated in Microsoft Word 2003 (Quest decided to use the formula editor)