A) (3/7 + 5/12) 4
First, find a common denominator for 7 and 12, which is 84.
Now convert the fractions:
3/7 = 36/84
5/12 = 35/84
Adding them together:
(36/84 + 35/84) = 71/84
Now multiply by 4:
71/84 4 = 284/84 = 71/21

Therefore, the value of the expression is 71/21.

B) (5/6 - 2/9) / 11
First, find a common denominator for 6 and 9, which is 18.
Now convert the fractions:
5/6 = 15/18
2/9 = 4/18
Subtracting them:
(15/18 - 4/18) = 11/18
Now divide by 11:
11/18 / 11 = 1/18

Therefore, the value of the expression is 1/18.