Lösungen/Solutions/
B1S2Ue/Ex1

L = Lektion/ Leçon   -- Sprechstunde / heures de consultation
W = Work / Arbeit / Travail
A  =Anhang/  Annexe / Appendice

Ueb/Ex 1      L

matrix = {{a, b, c}, {d, e, f}, {g, h, i}}; 
    vector = Transpose[{{r, s, t}}];
matrix // MatrixForm

matrix . vector

vector1 = {r, s, t};
matrix . vector1