cy, 66 bytes

Result

WA

Duration

547ms

Code [DL]

"\\#{require'matrix';*b=$<.map \&:split;p Matrix[*b,[1]*4].det/6}"

stdin

75 65 13
99 62 82
43 14 79
57 07 26

stdout

stderr

RubyError
	@ `"\\#{require'matrix';*b=$<.map &:split;p Matrix[*b,[1]*4].det/6}"' (0:0)
/root/cy.rb:566:in `eval': row size differs (4 should be 3) (ExceptionForMatrix::ErrDimensionMismatch)
	from /usr/local/ruby-2.5.0/lib/ruby/2.5.0/matrix.rb:69:in `each'
	from /usr/local/ruby-2.5.0/lib/ruby/2.5.0/matrix.rb:69:in `rows'
	from /usr/local/ruby-2.5.0/lib/ruby/2.5.0/matrix.rb:52:in `[]'
	from (eval):1:in `block in string'
	from /root/cy.rb:566:in `eval'
	from /root/cy.rb:566:in `block in string'
	from /root/cy.rb:665:in `block in exec'
	from /root/cy.rb:660:in `each'
	from /root/cy.rb:660:in `exec'
	from /root/cy.rb:777:in `block (3 levels) in <main>'
	from /root/cy.rb:844:in `<main>'

strace