clear
clc
AB=xlsread('data3_7.xls');
[m,nb]=size(AB);
n=nb-1;
A=AB(1:m,1:n);
B=AB(1:m,nb);
j=1;
for i=1:m
    b(i)=AB(i,j);
    j=j+1;
    continue;
end
j=1;
for i=2:m
    a(i)=AB(i,j);
    j=j+1;
    continue;
end
i=1;
for j=2:m
    c(i)=AB(i,j);
    i=i+1;
    continue;
end
d=B;
R=zeros(m,1);
R(1)=AB(1,1);
l=zeros(m,1);
y=AB(1,nb);
for i=2:m
       l(i)=a(i)/R(i-1);
       R(i)=b(i)-l(i)*c(i-1);
       y(i)=d(i)-l(i)*y(i-1);
end
x=zeros(m,1);
x(m)=y(m)/R(m);
for i=m-1:-1:1
    x(i)=(y(i)-c(i)*x(i+1))/R(i);
end
for k=1:n
    fprintf('x[%d]=%f\n',k,x(k));
end