Given the matrices AA and BB shown below, find 2, A, plus, one third, B, .2A+ 3 1 B. A, equals, open square bracket, begin matrix row 1, column 1, 6 row 1, column 2, 3 row 1, column 3, 0 end matrix , close square bracket, B, equals, open square bracket, begin matrix row 1, column 1, 9 row 1, column 2, 6 row 1, column 3, minus, 9 end matrix , close square bracket A=[ 6 3 0 ]B=[ 9 6 −9 ]