A=[3 -0.1 -0.2; 0.1 7 -0.3; 0.3 -0.2 10];
B=[7.85 -19.3 71.4]';
n=length(B)
%initial guess
x=[10 10 10]';
tolerance=1e-5;
err=1;
while (err>tolerance)
	for ii=1:n
		summ=0;
		for jj=1:n
			if (jj==ii)
				%do nothing
			else
				summ=summ+A(ii,jj)*x(jj);
			end
		end
	newx(ii)=(1/A(ii,ii))*(B(ii)-summ);
	errr(ii)=abs((newx(ii)-x(ii))/newx(ii))*100;
	end
x=newx;
err=max(errr);
end
x