Simplify: 1 3 (6ab - 9b) 2 3 (9ab 12b)
1,3(6ab−9b)×2,3×9×12ab×b 3(6ab−9b)×2 to 6(6ab−9b)1,6(6ab−9b),3×9×12ab×b 3×9×12ab×b to 324ab^21,6(6ab−9b),324ab^2