thực hiện phép tính (hợp lí nếu có thể):
a) 1\(\frac{4}{23}\)+\(\frac{5}{21}\)- \(\frac{4}{23}\)+ 0,5 + \(\frac{16}{21}\)
b) \(\frac{3}{7}\). 19\(\frac{1}{3}\)- \(\frac{3}{7}\). 33\(\frac{1}{3}\)
c) 9 . (-\(\frac{1}{3}\))\(^3\)+ \(\frac{1}{3}\)
d) 15\(\frac{1}{4}\): (-\(\frac{5}{7}\)) - 25\(\frac{1}{4}\): (-\(\frac{5}{7}\))