Replace A,B,C by suitable numberals:

Replace A,B,C,D by suitable numerals in the following ({:(," "6AB5),(,+D58C):})/(" "9351)

Replace A,B and C by suitable numerals.

Replace A,B and C by suitable numerals. ({:(," "5A),(,+87):})/(" "C B3)

Replace A,B and C by suitable numerals. ({:(," "AB),(," "xx3):})/(" "CAB)

Replace A,B and C by suitable numerals. ({:(," "6A),(,-AB):})/(" "37)

Replace A,B and C by suitable numerals. ({:(," "4CB6),(,+369A):})/(" "8173)

Replace A,B and C by suitable numerals. ({:(," "CB5),(,-28A):})/(" "259)

Teacher wrote on the blackboard as AB rarr C+D . Replace it with suitable substances. What type of reaction is it ?