Which of the following has/have value equal to zero?

82712351643=82741−241−2            R3→R3−R2 and R2→R2−R1=01/aa2bc1/bb2ac1/cc2ab=1abc1a3abc1b3abc1c3abc             R1→aR1,R2→bR2,R3→cR3                      =abcabc1a3abc1b3abc1c3abc              [taking abc common from C3] =0a+b2a+b3a+b2a+b3a+b4a+b4a+b5a+b6a+b=a+b2a+b3a+baaa2a2a2a                  R3→R3−R2,R2→R2−R1 = 0243673543172=216774332              C2→C2−7C3 =116074032             C1→C1−C2 =2