function [x]=gauss(A,b)
n=length(b);
dreiecksform(A,b)
% Rueckwertssubstitution
x=zeros(n,1);
for i=n:-1:1
	x(i) = (b(i)-A(i,i+1:n)*x(i+1:n)) / A(i,i);
end
linsolve(A,b);