Tính hợp lí :

A = \(\dfrac{-2}{9}\) + \(\dfrac{-3}{4}\) + \(\dfrac{3}{5}\) + \(\dfrac{1}{15}\) + \(\dfrac{1}{57}\) + \(\dfrac{1}{3}\) + \(\dfrac{-1}{36}\)

B = \(\dfrac{1}{2}\) + \(\dfrac{-1}{5}\) + \(\dfrac{-5}{7}\) + \(\dfrac{1}{6}\) + \(\dfrac{-3}{35}\) + \(\dfrac{1}{3}\) + \(\dfrac{1}{41}\)

C =  \(\dfrac{-1}{2}\) + \(\dfrac{3}{5}\) + \(\dfrac{-1}{9}\) + \(\dfrac{1}{127}\) + \(\dfrac{-7}{18}\) + \(\dfrac{4}{35}\) + \(\dfrac{2}{7}\)

\(\dfrac{-1}{3}.\dfrac{2}{5}\)

\(\dfrac{-3}{7}.\dfrac{4}{15}\)

\(\dfrac{-9}{3}.\dfrac{15}{27}\)

\(\dfrac{-5}{6}.\)( -12 )

\(\dfrac{-12}{4}.\dfrac{8}{9}\)

\(-3.\dfrac{7}{6}\)

\(\dfrac{-15}{9}.\dfrac{27}{5}\)

\(-9.\dfrac{4}{27}\)

Tính

a.\(\dfrac{4}{9}+\dfrac{3}{7}\)    \(\dfrac{3}{4}+\dfrac{7}{24}\)   \(\dfrac{1}{3}+\dfrac{2}{9}+\dfrac{4}{27}\)

b.\(\dfrac{5}{6}-\dfrac{3}{8}\)     \(\dfrac{7}{15}-\dfrac{11}{30}\)    \(\dfrac{2}{3}+\dfrac{1}{6}-\dfrac{7}{12}\)

c.\(\dfrac{18}{25}\times\dfrac{15}{6}\)    \(\dfrac{30}{49}:\dfrac{6}{7}\)      \(\dfrac{1}{2}\times\dfrac{3}{4}:\dfrac{6}{5}\)

d.\(8\times\dfrac{3}{5}:\dfrac{12}{5}\)     \(4:\dfrac{9}{5}:\dfrac{10}{3}\)

3 bn đầu tiên xong mik sẽ tick

Tính (Tính hợp lí nếu có thể)

a) \(\dfrac{-7}{12}\)-\(\dfrac{3}{36}\)

b) (4-\(\dfrac{5}{12}\)):2+\(\dfrac{5}{24}\)

c) \(\dfrac{8}{9}\)+\(\dfrac{1}{9}\).\(\dfrac{2}{13}\)+\(\dfrac{1}{9}\).\(\dfrac{11}{13}\)

d) \(\dfrac{3}{4}\).\(\dfrac{8}{9}\).\(\dfrac{15}{16}\).  ...  .\(\dfrac{9999}{10000}\)

e) \(\dfrac{3}{1.4}\)+\(\dfrac{3}{4.7}\)+\(\dfrac{3}{7.10}\)+...+\(\dfrac{3}{97.100}\)

*Lưu ý: Mong các anh chị trình bày chi tiết để em có thể hiểu bài, em xin các anh chị đừng viết mỗi kết quả xong em chả biết một cái gì ;-;

Câu 1 :\(\dfrac{-5}{7}.\dfrac{7}{-45}\);\(\dfrac{-3}{10}.\left(-30\right)\);\(-12.\dfrac{-2}{36}\)

Câu 2: \(\dfrac{3}{4}+\dfrac{1}{8}.\dfrac{-16}{5};\dfrac{7}{15}-\dfrac{18}{21}.\dfrac{7}{9}\)

Câu 3: \(\left(\dfrac{-5}{9}+\dfrac{3}{5}\right).\dfrac{3}{10};\left(\dfrac{3}{9}-\dfrac{2}{5}\right).\dfrac{-3}{10}\)

Câu 4: \(\left(\dfrac{3}{7}+\dfrac{1}{3}\right).\left(\dfrac{1}{8}-\dfrac{1}{2}\right);\left(\dfrac{-9}{12}-\dfrac{16}{30}\right).\left(\dfrac{-18}{22}-\dfrac{6}{11}\right)\)

Càn gấp

Tính rồi rút gọn (theo mẫu):

a) \(\dfrac{1}{8}+\dfrac{5}{8}\)                         b) \(\dfrac{1}{15}+\dfrac{4}{15}\)                     c) \(\dfrac{5}{9}+\dfrac{7}{9}\)                         d) \(\dfrac{23}{100}+\dfrac{27}{100}\)