$i=L,M,N,O,P,Q,R.$

Min

$s.t.$

Area $1$

Area $2$

Area $3$ Area $3$

Area $4$

Area $5$

Area $6$

Area $7$

$x_i=0,1$ for $i=L,M,N,O,P,Q,R$

$(b)$ Build a spreadsheet model for this problem. Solve the model. Which locations are chosen? $(Select$ all that apply.$)$

Substation $L$

Substation $M$

Substation $N$

Substation $O$

Substation $P$

Substation $Q$

Substation $R$