<Tr> <Th_colspan="6"> show Associated coefficient matrix </Th> </Tr> <Tr> <Th> </Th> <Th> </Th> <Th> </Th> <Th> d </Th> <Th> </Th> <Th> line </Th> </Tr> <Tr> <Td> </Td> <Td> 0 </Td> <Td> </Td> <Td> </Td> <Th> </Th> <Td> </Td> </Tr> <Tr> <Td> 0 </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Th> 0 </Th> <Td> </Td> </Tr>

Which of the following is not a one of the 3 basic classes of problems