The following is a facilities location integer programming model that I need to solve using excel. There's a 42x42 matrix that's too big to include here.

Decision Variables:
Xi = 1 if a service facility centre is placed in county i, 0 if not
Yi = 1 if it possible to place a service facility centre in county i, 0 if not
i = 1,2,42
Objective Function:
Max 12251 Y1 + 15355 Y2 + + 48927 Y42
Constraints:
X1 + X2 + X3 + + X42 <= 8	No more than 8 service facility centres can be placed
X1 + X2 + X18 + X19 >= Y1	County 1
X1 + X2 + X3 + X17 + X18 >= Y2	County 2
X33 + X34 + X39 + X40 + X42>= Y42	County 42
Xi,Yi = 0 or 1	Decision variables are binary