param N := 3;

var x{1..N} >= 0;
param a{1..8,1..3};
param c{1..8}:= 1;

minimize f:
sum {j in 1..8} c[j]*(sum {i in 1..3} (a[j,i] - x[i])^2)^0.5;

subject to cons1:
30 - 3*x[1] - 3*x[3] >= 0;

data;
var x:=
1	0
2	2
3	0;

param a:
	1	2	3:=
1	0	0	0
2	10	0	0
3	10	10	0
4	0	10	0
5	0	0	10
6	10	0	10
7	10	10	10
8	0	10	10;

	

solve;

display x;