www . seprodstore . com 79 7 Let 1 0 1 2 3 1 2 2 0 � � � � � �� � � � � � A and 2 2 3 3 3 4 2 3 x x x x � � � � � � � B . ( a ) Write down det A . [ 1 ] ( b ) Find det B . [ 2 ] ( c ) Solve the equation 4det det � A B . [ 2 ] ( a ) 8 A1 [ 1 ] ( b ) 2 3 2 3 det ( 3 )( 3 ) ( 4 )( 2 ) x x x x � � B ( A1 ) for substitution 5 5 det 9 8 x x � � B 5 det x � B A1 [ 2 ] ( c ) 4det det � A B 5 4 ( 8 ) x � � ( M1 ) for setting equation 5 32 x � 2 x � A1 [ 2 ] Example Solution 25 Paper 1 – Matrix Algebra