gauss method in matlab

Hi all, i am making a code to solve a system of equations but i am geting the wrong result. function resolucao = resolve(A,B) a = det(A); if(a==0) fprintf('Sistema impossível ou com infinitas soluções.\n') else if A(1,1) == 0 A(2,2) == 0 A(2,2) == 0 A(3,3) == 0 fprintf('Método inválido para elementos na diagonal principal iguais a zero.\n') else for j = 3:-1:2 if A(j,1) == 0 B(j,1) = B(j,1); else B(j,1) = -A(1,1)/A(j,1)*B(j,1)+B(1,1) end if A(j,1)==0 for k=1:3 A(j,k)=A(j,k) end else for i = 1:3 A(j,i) = -A(1,1)*A(j,i)/A(j,1)+A(1,i) end end end for i2=2:3 if A(3,2) == 0 B(3,1) = B(3,1); else B(3,1) = -A(2,2)/A(3,2)*B(3,1) + B(2,1) end if A(3,2) == 0 A(3,i2) = A(3,i2); else A(3,i2) = -A(2,2)/A(3,2)*A(3,i2) + A(2,i2) end end x3 = B(3,1)/A(3,3) x2 = (B(2,1)-A(2,3)*x3)/A(2,2) x1 = (B(1,1)-A(1,2)*x2-A(1,3)*x3)/A(1,1) end end end

cheers!