thực hiện phép tính
a, \(\dfrac{5}{6}+\left(\dfrac{-1}{2}\right)+\dfrac{3}{4}\)
b,\(\left(0,75-\dfrac{1}{3}\right):\dfrac{7}{15}\)
c,\(\dfrac{7}{12}-\dfrac{3}{4}.\dfrac{5}{6}\)
d,\(\left(2\dfrac{1}{3}+1\dfrac{3}{4}\right).\dfrac{12}{13}\)
Giúp mk với