$\frac{7}{15}+\frac{14}{45}+\frac{21}{135}+\frac{28}{345}+\frac{35}{759}$
\(\frac{7}{15}+\frac{14}{45}+\frac{21}{135}+\frac{28}{345}+\frac{35}{759}\)
Tính nhanh nếu có thể:
a)
\(\frac{1}{3}+\frac{1}{15}+\frac{1}{35}+\frac{1}{63}+\frac{1}{99}+\frac{1}{143}+\frac{1}{195}\)
b)
\(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+\frac{1}{45}+\frac{1}{55}+\frac{1}{66}\)
Bài 1: Thực hiện phép tính
a) \(\frac{-3}{14}-\frac{5}{-14}\)
b)\(\frac{-5}{4}-\frac{3}{4}\)
c)\(\frac{15}{6}-\frac{-10}{20}\)
d)\(\frac{26}{-35}-\frac{6}{35}\)
Bài 2:Thực hiện phép tính
a)\(\frac{-1}{21}-\frac{-1}{28}\)
b)\(\frac{-3}{29}-\frac{-1}{59}\)
c)\(\frac{8}{40}-\frac{-36}{45}\)
d)\(\frac{-8}{18}-\frac{-36}{45}\)
e)\(\frac{3}{-15}-\frac{-1}{6}\)
Các bạn giúp mình nhé!!!!!
1+\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+\frac{1}{45}\)
1) tính giá trị biểu thức:
a)-1\(\frac{5}{7}.15+\frac{2}{7}\left(-15\right)+\left(-105\right)\left(\frac{2}{3}-\frac{4}{5}+\frac{1}{7}\right)\)
b)\(\frac{3}{14}:\frac{1}{28}-\frac{13}{21}:\frac{1}{28}+\frac{49}{42}:\frac{1}{28}-6\)
c)\(4.\left(-\frac{1}{2}\right)^3-2.\left(-\frac{1}{2}\right)^2+3.\left(-\frac{1}{2}\right)+1\)
Tính nhanh phân số \(A=\frac{7}{5}+\frac{7}{15}+\frac{7}{45}+\frac{7}{135}+\frac{7}{405}+\frac{7}{1215}\)
Tính:
a, \(\frac{-28}{19}.\frac{\left(-38\right)}{14}\)
b, \(\frac{-21}{16}.\frac{\left(-24\right)}{7}\)
c, \(\frac{12}{17}.\frac{\left(-34\right)}{9}\)
d, \(\frac{\left(-15\right)}{4}:\frac{21}{10}\)
e,\(-2\frac{1}{7} :-1\frac{1}{14}\)
Giúp mình với các bạn, mình đang cần gấp xin các bạn giúp mình nhé
\(\frac{1}{2}.\left(\frac{2}{9}+\frac{3}{7}-\frac{5}{27}\right);\left(\frac{-5}{28}+1,75+\frac{8}{35}\right):\left(-3\frac{9}{20}\right);\frac{1}{3}.\frac{5}{7}-\frac{7}{27}.\frac{36}{14};70,5-528:\frac{15}{2}\)