© SE Production Limited 26 All Rights Reserved 2021 17 . Let 2 1 3 5 1 1 3 q p � � � � � � � � � � � � � � A , where p , q� . It is given that 1 0.4 0.2 0.2 0.1 0.7 1.2 0.1 0.3 0.8 � � � � � � � � � � � � � � A . ( a ) Find p and q . [ 3 ] ( b ) Hence , solve the system 4 2 2 3 7 12 5 3 8 9 x y z x y z x y z � � � � � � � � � � � � � � . [ 5 ]