If | X-1 | + | X-2 | + | x-3 | + +|If x-2007 | is greater than or equal to a for all real numbers x, then the value range of real number a is? Well

If | X-1 | + | X-2 | + | x-3 | + +|If x-2007 | is greater than or equal to a for all real numbers x, then the value range of real number a is? Well

|x-1|+|x-2|+|x-3|+…… +|X-2007 | > = 2 (1 + 2 +. 1004) = 1000925, so a is less than or equal to 1000925
Using the absolute value inequality | X1 + | x2 + | X3 +. + | xn | > = | X1 + x2 +. Xn|
Write the first 1003 items as | 1-x | + | 2-x | + | 3-x | +. | 1003-x|
The last is | 1 + 2 + 3 +... 1003-1004-1005 -... 2007 | + | x-2004 | > = | 1000925|

If x and y satisfy the constraint condition x − y + 1 ≥ 0 x + y − 3 ≤ 0 x + 3 y − 3 ≥ 0, then the minimum value of Z = 3x-y is 0______ ．

Make the plane region represented by the inequality system X − y + 1 ≥ 0 x + y − 3 ≤ 0 x + 3Y − 3 ≥ 0, as shown in the figure, y = 3x-z can be obtained from z = 3x-y, then - Z represents the intercept of the line 3x-y-z = 0 on the Y axis, and the larger the intercept, the smaller the Z. according to the graph, when the line z = 3x-y passes through point C, Z is the minimum, and C (0,1) can be obtained from x + 3Y − 3 = 0 x − y + 1 = 0, then z = - 1, so the answer is: - 1