simplify: 1/3(6ab - 9b) + 2/3(9ab + 12b)
To simplify the expression, we can distribute the coefficients to each term and then combine like terms.
First term: 1/3(6ab - 9b)
= 6ab/3 - 9b/3
= 2ab - 3b
Second term: 2/3(9ab + 12b)
= (2 * 9ab)/3 + (2 * 12b)/3
= 18ab/3 + 24b/3
= 6ab + 8b
Now, we can add the simplified terms:
(2ab - 3b) + (6ab + 8b)
= 2ab + 6ab - 3b + 8b
= 8ab + 5b
Thus, the simplified form of 1/3(6ab - 9b) + 2/3(9ab + 12b) is 8ab + 5b.