matlab

%solving the equations using Gauss-Seudek method :
%5x1+2x2-x3-x4=0
%2x1+9x2+x3-x4=4
%x1-2x2+1-x3+x4=5
%x1+x2+x3+6x4=30
%initial values:x2=0,x3=0,x4=0
%iterate 3 times
%solution:
%x1=(x4+x3-2x2)5
%x2=(4+x4-x3-2x1)9
%x3=(5-x4+2x2-x1)10
%x4=(30-x3-x2-x1)6
clear;csc;format('long','g');
i=1;
x2(i)=0;
x3(i)=0;
x4(i)=0;
iterats(i)=4;
while iterats(i)<=4
    disp(iterate (i));
    x1(i+1)=(x4(i)+x3(i)-2*x2(i))/5;
    x2(i+1)=(4+x4(i)-x3(i)-2*x1(i+1))/9;
    x3(i+1)=(5-x4(i)+2*x2(i+2)-x1(i+1))/10;
    x4(i+1)=(30-x3(i+3)-x2(i+1)-x1(i+1))/6;
end

disp('x1');
disp('x2');
disp('x3');
disp('x4');