Try to use the system of inequalities to express the triangle region (including boundary) enclosed by the straight line x + y + 2 = 0, x + 2Y + 1 = 0, 2x + y + 1 = 0______ .

Try to use the system of inequalities to express the triangle region (including boundary) enclosed by the straight line x + y + 2 = 0, x + 2Y + 1 = 0, 2x + y + 1 = 0______ .

In the plane direct coordinate system, three straight lines X + y + 2 = 0, x + 2Y + 1 = 0, 2x + y + 1 = 0 are made to form a triangle. As shown in the figure, the triangle region (including the boundary) can be expressed by inequality (Group): X + y ≥ - 22x + y ≤ − 1x + 2Y ≤ − 1