A=zeros(5);
Q01=6;
c01=20;
Q03=7;
c03=50;
Q31=3;
Q23=2;
Q12=4;
Q25=1;
Q15=5;
Q55=4;
Q54=2;
Q24=1;
Q34=6;
Q44=9;
A(1,2)=-Q12;
A(1,3)=Q31;
A(1,5)=-Q15;
A(2,1)=Q12;
A(2,2)=-(Q24+Q25+Q23);
A(3,2)=Q23;
A(3,3)=-(Q31+Q34);
A(4,2)=Q24;
A(4,3)=Q34;
A(4,4)=-Q44;
A(4,5)=Q54;
A(5,1)=Q15;
A(5,2)=Q25;
A(5,5)=-(Q55+Q54);
B=zeros(5,1);
B(1,1)=Q01*c01;
B(3,1)=Q03*c03;
ans=inv(A)*B