4. tính
a. A=\(\dfrac{1}{3}\).\(\dfrac{4}{5}\)+\(\dfrac{1}{3}\).\(\dfrac{6}{5}\)+\(\dfrac{2}{3}\)
b. B=\(\dfrac{-5}{6}\).\(\dfrac{4}{19}\)+\(\dfrac{-7}{12}\).\(\dfrac{4}{19}\)-\(\dfrac{40}{57}\)
c. C=\(\dfrac{3}{7}\).\(\dfrac{9}{26}\)-\(\dfrac{1}{14}\).\(\dfrac{1}{13}\)-\(\dfrac{1}{7}\)
Loga
Toán lớp 6
