\(\frac{2}{3}x\frac{5}{6}x\frac{9}{10}x\frac{14}{15}x\frac{20}{21}x\frac{27}{28}\)
\(\frac{1}{5}+\frac{4}{10}+\frac{9}{15}+\frac{16}{20}+\frac{25}{25}+\frac{36}{30}+\frac{49}{35}+\frac{64}{40}+\frac{81}{45}\)=?
tính nhanh giá trị của biểu thức: A=\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+\frac{1}{45}\)
D=\(\frac{1}{10}+\frac{1}{15}+\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+\frac{1}{45}\)
E=\(\frac{10}{56}+\frac{10}{140}+\frac{10}{260}+.....\frac{10}{1400}\)
\(\frac{14}{16}\) - \(\frac{6}{21}\)
\(\frac{9}{22}\) - \(\frac{9}{33}\)
\(\frac{8}{15}\)+ \(\frac{4}{21}\)
\(\frac{15}{24}+2\)
\(\frac{4}{5}-\frac{1}{3}+\frac{1}{2}\)
\(\frac{5}{6}+\frac{3}{8}+\frac{1}{10}\)
\(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}\)
Tính tổng \(A=\frac{38}{25}+\frac{9}{10}-\frac{11}{15}+\frac{13}{21}-\frac{15}{28}+\frac{17}{36}-...+\frac{197}{4851}-\frac{199}{4950}\)
Tính nhanh:
a)\(\frac{5}{30}+\frac{15}{90}+\frac{25}{150}+\frac{35}{210}+\frac{45}{270}\)
b)\(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+...+\frac{1}{56}\)
c)\(\frac{1}{15}+\frac{4}{30}+\frac{2}{45}+\frac{16}{60}+\frac{25}{75}+\frac{36}{90}+\frac{49}{105}+\frac{64}{120}+\frac{81}{135}\)
Tinhs giá trị biểu thức ::
a) 8,3 x 39 - 2,93 x 500 + 19,3 x 20
b) \(3\frac{3}{2}\times\frac{3}{17}+\frac{4}{9}\times\frac{27}{8}-\frac{1}{3}\)
c)9,31 : 6 + 13,8 : 6 -5,11 : 6
d) \(\frac{19,8\div0,2\times44,44\div0,5\times13,2\div0,25}{3,3\times88,88\div0,5\times6,6\div0,125\times5}\)
e) \(\frac{5}{1.6}+\frac{5}{6.11}+...+\frac{5}{501.506}\)
f) \(\frac{\frac{4}{7}+\frac{12}{13}+\frac{16}{17}-\frac{8}{27}}{\frac{5}{21}+\frac{15}{39}+\frac{20}{51}-\frac{10}{81}}\)
Tính nhanh \(\frac{1}{5}+\frac{4}{10}+\frac{9}{15}+\frac{16}{20}+\frac{36}{30}+\frac{64}{40}+\frac{81}{45}\)