OpenStudy (anonymous):

hI... how to proof (AXB).(CXD)+(BXC).(AXD)+(CXA).(BXD)=0

7 years ago
OpenStudy (shadowfiend):

Hm. Are you trying to prove that without any information at all about A, B, C, and D?

7 years ago
OpenStudy (anonymous):

Distribute terms AC+AD+BC+BD+AB+BD+AC+CD+BC+CD+AB+AD=0 2AC+2AD+2BC+2BD+2AB+2CD=0 AC+AD+BC+BD+AB+CD=0 At this point, it depends on the values or restrictions on A, B, C, and D

7 years ago