Ôn tập toán 6
Các câu hỏi tương tự
\(\dfrac{1}{21}+\dfrac{1}{28}+\dfrac{1}{36}+...+\dfrac{1}{x.\left(x+1\right):2}=\dfrac{2}{9}\)
tìm x,biết:
\(\dfrac{1}{21}+\dfrac{1}{28}+\dfrac{1}{36}+........+\dfrac{2}{x\left(x+1\right)}=\dfrac{2}{9}\)
Bài 6 tính
\(A=\dfrac{1}{2}+\dfrac{1}{2^2}+\dfrac{1}{2^3}+...+\dfrac{1}{2^{10}}\)
\(F=\dfrac{1}{15}+\dfrac{1}{21}+\dfrac{1}{28}+...+\dfrac{1}{190}\)
\(G=\dfrac{12}{84}+\dfrac{12}{210}+\dfrac{12}{390}+...+\dfrac{12}{210}\)
1 Tính
a)\(\dfrac{1}{3}+\dfrac{1}{6}+\dfrac{1}{9}+\dfrac{1}{18}=\)
b)\(\dfrac{42}{24}-\dfrac{10}{8}-\dfrac{2}{4}=\)
c) \(\dfrac{1}{6}+\dfrac{1}{12}+\dfrac{1}{20}+..............+\dfrac{1}{90}\)
giúp mik nha ,mik kb
Tính:\(A=\dfrac{1}{21}+\dfrac{1}{28}+\dfrac{1}{36}+\dfrac{1}{45}+...+\dfrac{1}{210}\)
Huhu giúp mik gấp nhé
Trưa mik thi rồi
Á huhu
Tìm x, biết :
a) left(dfrac{31}{20}-dfrac{26}{45}right).dfrac{-36}{35} x left(dfrac{51}{56}+dfrac{8}{21}+dfrac{1}{3}right).dfrac{8}{13}
b) dfrac{-3}{5}.xdfrac{1}{4}+0,75
c) left(dfrac{1}{7}-dfrac{1}{3}right).xdfrac{28}{3}.left(dfrac{1}{4}-dfrac{1}{7}right)
d) dfrac{5}{7}.xdfrac{9}{8}-0,125
e)left(dfrac{2}{11}+dfrac{1}{3}right).xleft(dfrac{1}{7}-dfrac{1}{8}right).56
Đọc tiếp
Tìm x, biết :
a) \(\left(\dfrac{31}{20}-\dfrac{26}{45}\right).\dfrac{-36}{35}< x< \left(\dfrac{51}{56}+\dfrac{8}{21}+\dfrac{1}{3}\right).\dfrac{8}{13}\)
b) \(\dfrac{-3}{5}.x=\dfrac{1}{4}+0,75\)
c) \(\left(\dfrac{1}{7}-\dfrac{1}{3}\right).x=\dfrac{28}{3}.\left(\dfrac{1}{4}-\dfrac{1}{7}\right)\)
d) \(\dfrac{5}{7}.x=\dfrac{9}{8}-0,125\)
e)\(\left(\dfrac{2}{11}+\dfrac{1}{3}\right).x=\left(\dfrac{1}{7}-\dfrac{1}{8}\right).56\)
Bài 1:Tính
a, Adfrac{3}{4}cdotdfrac{8}{9}cdotdfrac{15}{16}cdot....cdotdfrac{9999}{10000}
b,Bleft(1-dfrac{1}{21}right)cdotleft(1-dfrac{1}{28}right)cdotleft(1-dfrac{1}{36}right)cdot....cdotleft(1-dfrac{1}{1326}right)
c,Cleft(1+dfrac{1}{1cdot3}right)cdotleft(1+dfrac{1}{2cdot4}right)cdotleft(1+dfrac{1}{3cdot5}right)cdot....cdotleft(1+dfrac{1}{99cdot101}right)
Đọc tiếp
Bài 1:Tính
a, A=\(\dfrac{3}{4}\cdot\dfrac{8}{9}\cdot\dfrac{15}{16}\cdot....\cdot\dfrac{9999}{10000}\)
b,B=\(\left(1-\dfrac{1}{21}\right)\cdot\left(1-\dfrac{1}{28}\right)\cdot\left(1-\dfrac{1}{36}\right)\cdot....\cdot\left(1-\dfrac{1}{1326}\right)\)
c,C=\(\left(1+\dfrac{1}{1\cdot3}\right)\cdot\left(1+\dfrac{1}{2\cdot4}\right)\cdot\left(1+\dfrac{1}{3\cdot5}\right)\cdot....\cdot\left(1+\dfrac{1}{99\cdot101}\right)\)
Giúp đi giúp nha không khó đâu cũng không dễ đâu:
a) \(\dfrac{1}{2}< A< 1\)
biết A= \(\dfrac{1}{21}+\dfrac{1}{22}+...+\dfrac{1}{40}\)
b) \(\dfrac{1}{26}+\dfrac{1}{27}+\dfrac{1}{28}+...+\dfrac{1}{50}=1-\dfrac{1}{2}+...+\dfrac{1}{49}-\dfrac{1}{50}\)
Tick cho!
a)dfrac{2}{7}+dfrac{-3}{8}+dfrac{11}{7}+dfrac{1}{7}_{ }+dfrac{5}{-8}
b)dfrac{3}{17}+dfrac{-5}{13}+dfrac{-18}{35}+dfrac{14}{17}+dfrac{17}{-35}_{ }+dfrac{-8}{13}
c)dfrac{-3}{8}+dfrac{12}{25}+dfrac{5}{-8}+dfrac{2}{-5}+dfrac{13}{25}
d)dfrac{-5}{21}+left(dfrac{-16}{21}+1right)
e)dfrac{-3}{17}+left(dfrac{2}{3}+dfrac{3}{17}right)
f)left(dfrac{-1}{6}+dfrac{5}{-12}right)+dfrac{7}{12}
Đọc tiếp
a)\(\dfrac{2}{7}+\dfrac{-3}{8}+\dfrac{11}{7}+\dfrac{1}{7}_{ }+\dfrac{5}{-8}\)
b)\(\dfrac{3}{17}+\dfrac{-5}{13}+\dfrac{-18}{35}+\dfrac{14}{17}+\dfrac{17}{-35}_{ }+\dfrac{-8}{13}\)
c)\(\dfrac{-3}{8}+\dfrac{12}{25}+\dfrac{5}{-8}+\dfrac{2}{-5}+\dfrac{13}{25}\)
d)\(\dfrac{-5}{21}+\left(\dfrac{-16}{21}+1\right)\)
e)\(\dfrac{-3}{17}+\left(\dfrac{2}{3}+\dfrac{3}{17}\right)\)
f)\(\left(\dfrac{-1}{6}+\dfrac{5}{-12}\right)+\dfrac{7}{12}\)