3. Let 1 2-1 A= 21 0 -12 a. Find the following elementary matrices. Name these matrices Ei. E , E 2, R3 + R1 R3 3, Ra + R2 R3 6, Ra + R1 R1 b. Apply left and right multiplication of EsE your answer to the comand window e. Which one between EE Eis and EE answer to the command window . El to A. Are they the same? Output Esls is the inverse of A? Output your