Tính giá trị các biểu thức sau:
a)A=\(\left[\left(-0,5\right)-\dfrac{2}{3}\right]:\left(-3\right)+\dfrac{1}{3}-\left(-\dfrac{1}{6}\right):\left(2\right)\)
b)B=\(\left(\dfrac{2}{25}-0,036\right):\left(\dfrac{11}{50}\right)-\left[\left(3\dfrac{1}{4}-2\dfrac{4}{9}\right)\right].\dfrac{9}{29}\)