Tính nhanh 

\(1.A=\dfrac{38}{39}-\dfrac{47}{45}-\dfrac{38}{39}+\dfrac{2}{45}\)

\(2.B=\dfrac{5}{3}.\dfrac{11}{19}-\dfrac{11}{19}.\dfrac{2}{3}-\dfrac{11}{3}.\dfrac{6}{19}\)

\(3.C=3.\dfrac{14}{17}-\dfrac{3}{17}.3+\dfrac{6}{17}.3\)

\(4.D=\dfrac{1-\dfrac{1}{3}-\dfrac{1}{5}}{2+\dfrac{1}{15}-\dfrac{1}{5}}\)

Tìm x:

a) \(\dfrac{2}{5}+\dfrac{3}{5}.x+-\dfrac{1}{4}\)

b) \(\dfrac{7}{9}-\dfrac{2}{9}.x=\dfrac{4}{3}\)

c) \(\left(\dfrac{3}{10}-x\right).\dfrac{-1}{3}=\dfrac{-2}{5}\)

d) \(\dfrac{1}{3}+\dfrac{1}{3}:x=-7\)

Tìm x:

a) \(\dfrac{2}{5}\) + \(\dfrac{3}{5}\) . x + \(\dfrac{-1}{4}\)

b) \(\dfrac{7}{9}\) - \(\dfrac{2}{9}\) . x = \(\dfrac{4}{3}\)

c) \(\left(\dfrac{3}{10}-x\right)\) . \(\dfrac{-1}{3}=\dfrac{-2}{5}\)

d) \(\dfrac{1}{3}+\dfrac{2}{3}:x=-7\)

Tìm x:

a) x + \(\dfrac{-3}{7}\) = \(\dfrac{4}{7}\)

b) \(\dfrac{3}{2}\) . x = \(\dfrac{-2}{3}\)

c)-5 \(\dfrac{4}{7}\) : x = 13

d) \(\dfrac{1}{2}\)x - 75% = \(\dfrac{1}{4}\)