Ôn tập toán 6
Các câu hỏi tương tự
\(\dfrac{1+\dfrac{1}{3}+\dfrac{1}{5}+...+\dfrac{1}{99}}{\dfrac{1}{1x99}+\dfrac{1}{3x97}+\dfrac{1}{5x95}...+\dfrac{1}{49x51}}\)Rút gọn biểu thức trên về tối giản
Tính giá trị biểu thức:
\(\dfrac{1+\dfrac{1}{3}+\dfrac{1}{5}+\dfrac{1}{7}+...+\dfrac{1}{97}+\dfrac{1}{99}}{\dfrac{1}{1\cdot99}+\dfrac{1}{3\cdot97}+\dfrac{1}{5\cdot95}+...+\dfrac{1}{97\cdot3}+\dfrac{1}{99\cdot1}}\)
tính tổng
Sdfrac{1}{1cdot2cdot3}+dfrac{1}{2cdot3cdot4}+dfrac{1}{3cdot4cdot5}+...+dfrac{1}{ncdotleft(n+1right)cdotleft(n+2right)}
A1+dfrac{1}{3}+dfrac{1}{5}+dfrac{1}{7}+...+dfrac{1}{99}
B dfrac{1}{2}+dfrac{1}{3}+dfrac{1}{4}+...dfrac{1}{100}
Cdfrac{99}{1}+dfrac{98}{2}+dfrac{97}{3}+...+dfrac{1}{99}
Đọc tiếp
tính tổng
S=\(\dfrac{1}{1\cdot2\cdot3}+\dfrac{1}{2\cdot3\cdot4}+\dfrac{1}{3\cdot4\cdot5}+...+\dfrac{1}{n\cdot\left(n+1\right)\cdot\left(n+2\right)}\)
A=1+\(\dfrac{1}{3}+\dfrac{1}{5}+\dfrac{1}{7}+...+\dfrac{1}{99}\)
B= \(\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+...\dfrac{1}{100}\)
C=\(\dfrac{99}{1}+\dfrac{98}{2}+\dfrac{97}{3}+...+\dfrac{1}{99}\)
tìm x biết
\(\left(\dfrac{1}{26}+\dfrac{1}{27}+...+\dfrac{1}{50}\right):x=\dfrac{99}{50}-\dfrac{97}{49}+...+\dfrac{7}{4}-\dfrac{5}{3}+\dfrac{3}{2}-1\)
Cho A=\(\dfrac{\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+...+\dfrac{1}{99}+\dfrac{1}{100}}{\dfrac{99}{1}+\dfrac{98}{2}+\dfrac{97}{3}+...+\dfrac{2}{98}+\dfrac{1}{99}}\)
Tính A
4 tháng 8 2017 lúc 16:29
Bài 1:
\(a)5\dfrac{1}{20}+\dfrac{8}{9}-\dfrac{15}{25}+\dfrac{75}{-18}\)
\(b)\dfrac{1}{15}+\dfrac{1}{35}+\dfrac{1}{63}+\dfrac{1}{99}+\dfrac{1}{143}\)
\(c)\dfrac{6}{7}+\dfrac{5}{7}:5-\dfrac{8}{9}.\dfrac{6}{7}+\dfrac{5}{8}:5-\dfrac{3}{16}.\left(-2\right)^2\)
K =\(\dfrac{1}{2}-\dfrac{1}{2^3}-\dfrac{1}{2^5}-\dfrac{1}{2^7}-.........-\dfrac{1}{2^{99}}\)
BT1: CMR:
a) dfrac{1}{2^2}+dfrac{1}{3^2}+dfrac{1}{4^2}+...+dfrac{1}{n^2} 1
b) dfrac{1}{4}+dfrac{1}{16}+dfrac{1}{36}+dfrac{1}{64}+dfrac{1}{100}+dfrac{1}{144}+dfrac{1}{196} dfrac{1}{2}
c) dfrac{1}{3}+dfrac{1}{30}+dfrac{1}{32}+dfrac{1}{35}+dfrac{1}{45}+dfrac{1}{47}+dfrac{1}{50} dfrac{1}{2}
d) dfrac{1}{2}-dfrac{1}{4}+dfrac{1}{8}-dfrac{1}{16}+dfrac{1}{32}-dfrac{1}{64} dfrac{1}{3}
e) dfrac{1}{3} dfrac{2}{3^2}+dfrac{3}{3^3}-dfrac{4}{3^4}+...+dfrac{99}{3^{99}}-dfrac{100}{3^{100}} dfrac{3}{16}
f) d...
Đọc tiếp
BT1: CMR:
a) \(\dfrac{1}{2^2}+\dfrac{1}{3^2}+\dfrac{1}{4^2}+...+\dfrac{1}{n^2}< 1\)
b) \(\dfrac{1}{4}+\dfrac{1}{16}+\dfrac{1}{36}+\dfrac{1}{64}+\dfrac{1}{100}+\dfrac{1}{144}+\dfrac{1}{196}< \dfrac{1}{2}\)
c) \(\dfrac{1}{3}+\dfrac{1}{30}+\dfrac{1}{32}+\dfrac{1}{35}+\dfrac{1}{45}+\dfrac{1}{47}+\dfrac{1}{50}< \dfrac{1}{2}\)
d) \(\dfrac{1}{2}-\dfrac{1}{4}+\dfrac{1}{8}-\dfrac{1}{16}+\dfrac{1}{32}-\dfrac{1}{64}< \dfrac{1}{3}\)
e) \(\dfrac{1}{3}< \dfrac{2}{3^2}+\dfrac{3}{3^3}-\dfrac{4}{3^4}+...+\dfrac{99}{3^{99}}-\dfrac{100}{3^{100}}< \dfrac{3}{16}\)
f) \(\dfrac{1}{41}+\dfrac{1}{42}+\dfrac{1}{43}+...+\dfrac{1}{79}+\dfrac{1}{80}>\dfrac{7}{12}\)
BT2: Tính tổng
a) A=\(\dfrac{1}{3}+\dfrac{1}{3^2}+\dfrac{1}{3^3}+...+\dfrac{1}{3^{100}}\)
b) E=\(1+\dfrac{1}{2}\left(1+2\right)+\dfrac{1}{3}\left(1+2+3\right)+\dfrac{1}{4}\left(1+2+3+4\right)+...+\dfrac{1}{200}\left(1+2+3+...+200\right)\)
BT3: Cho S=\(\dfrac{3}{10}+\dfrac{3}{11}+\dfrac{3}{12}+\dfrac{3}{13}+\dfrac{3}{14}\)
CMR: 1 < S < 2
1 thực hiện phép tính
a,dfrac{-2}{3}+dfrac{3}{4}-dfrac{-1}{6}+dfrac{-2}{6}-dfrac{-2}{5}
b,dfrac{-2}{3}+dfrac{-1}{5}+dfrac{3}{4}-dfrac{5}{6}-dfrac{-7}{10}
c,dfrac{1}{2}-dfrac{-2}{5}+dfrac{1}{3}+dfrac{5}{7}-dfrac{-1}{6}+dfrac{-4}{35}+dfrac{1}{41}
d,dfrac{1}{100.99}-dfrac{1}{99.98}-dfrac{1}{98.97}-...-dfrac{1}{3.2}-dfrac{1}{2.1}
Đọc tiếp
1 thực hiện phép tính
a,\(\dfrac{-2}{3}+\dfrac{3}{4}-\dfrac{-1}{6}+\dfrac{-2}{6}-\dfrac{-2}{5}\)
b,\(\dfrac{-2}{3}+\dfrac{-1}{5}+\dfrac{3}{4}-\dfrac{5}{6}-\dfrac{-7}{10}\)
c,\(\dfrac{1}{2}-\dfrac{-2}{5}+\dfrac{1}{3}+\dfrac{5}{7}-\dfrac{-1}{6}+\dfrac{-4}{35}+\dfrac{1}{41}\)
d,\(\dfrac{1}{100.99}-\dfrac{1}{99.98}-\dfrac{1}{98.97}-...-\dfrac{1}{3.2}-\dfrac{1}{2.1}\)