Đại số lớp 7
Các câu hỏi tương tự
TÍNH:
1)\(\dfrac{9}{10}-\dfrac{1}{90}-\dfrac{1}{72}-\dfrac{1}{56}-\dfrac{1}{42}-\dfrac{1}{30}-\dfrac{1}{20}-\dfrac{1}{12}-\dfrac{1}{6}-\dfrac{1}{2}\)
2)\(\dfrac{_{-5}}{11}.\dfrac{13}{17}-\dfrac{5}{11}.\dfrac{4}{17}\)
a) Tính nhanh : A = \(\dfrac{1}{2}+\dfrac{5}{6}+\dfrac{11}{12}+\dfrac{19}{20}+\dfrac{29}{30}+\dfrac{41}{42}+\dfrac{55}{56}+\dfrac{71}{72}+\dfrac{89}{90}+\dfrac{109}{110}\)
b) Tìm 3 số tự nhiên khác nhau có tổng nghịch đảo của chúng bằng một số tự nhiên
Tính nhanh:
a, \(\dfrac{8}{9}-\dfrac{1}{72}-\dfrac{1}{56}-\dfrac{1}{42}-\dfrac{1}{30}-\dfrac{1}{20}-\dfrac{1}{12}-\dfrac{1}{6}-\dfrac{1}{2}\)
b, \(\left(-\dfrac{1}{4}+\dfrac{7}{35}-\dfrac{5}{3}\right)-\left(-\dfrac{15}{12}+\dfrac{6}{11}-\dfrac{48}{49}\right)\)
2/6+9/20-11/30+13/42-15/56+17/72-19/90+21/110-23/132
Bài 1:1/left(-dfrac{25}{13}right)+left(-dfrac{19}{17}right)+dfrac{12}{13}+left(-dfrac{25}{17}right) 6/ 2dfrac{2}{15}.dfrac{9}{17}.dfrac{3}{32}:left(-dfrac{3}{17}right)2/dfrac{1}{2}-left(-dfrac{1}{3}right)+dfrac{1}{23}+dfrac{1}{6} 7/left(dfrac{-3}{4}+dfrac{2}{5}right):dfrac{3}{7}+left(dfrac{3}{5}+dfrac{-1}{4}right):dfrac{3}{7}3/left(-dfrac{3}{7}right).dfrac{5}{11}+left(-dfrac{5}{14}right).dfrac{5}{11} ...
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Bài 1:
1/\(\left(-\dfrac{25}{13}\right)+\left(-\dfrac{19}{17}\right)+\dfrac{12}{13}+\left(-\dfrac{25}{17}\right)\) 6/ \(2\dfrac{2}{15}.\dfrac{9}{17}.\dfrac{3}{32}:\left(-\dfrac{3}{17}\right)\)
2/\(\dfrac{1}{2}-\left(-\dfrac{1}{3}\right)+\dfrac{1}{23}+\dfrac{1}{6}\) 7/\(\left(\dfrac{-3}{4}+\dfrac{2}{5}\right):\dfrac{3}{7}+\left(\dfrac{3}{5}+\dfrac{-1}{4}\right):\dfrac{3}{7}\)
3/\(\left(-\dfrac{3}{7}\right).\dfrac{5}{11}+\left(-\dfrac{5}{14}\right).\dfrac{5}{11}\) 8/\(\left(-\dfrac{1}{3}\right).\left(-\dfrac{15}{19}\right).\dfrac{38}{45}\)
4/\(\left(-\dfrac{5}{11}\right).\dfrac{7}{15}.\dfrac{11}{-5}.\left(-30\right)\) 9/\(\dfrac{1}{2.3}+\dfrac{1}{3.4}+\dfrac{1}{4.5}+......+\dfrac{1}{19.20}\)
5/\(\left(-\dfrac{5}{9}\right).\dfrac{3}{11}+\left(-\dfrac{13}{18}\right).\dfrac{3}{11}\) 10/\(\dfrac{1}{9.10}-\dfrac{1}{8.9}-\dfrac{1}{7.8}-......-\dfrac{1}{2.3}-\dfrac{1}{1.2}\)
-(\(\dfrac{3}{17}\)+\(\dfrac{2}{13}\))-(\(\dfrac{-20}{17}\)+\(\dfrac{11}{13}\)) Tính nhanh từng bước ra nha
Thực hiện phép tính:
a) 1dfrac{4}{23}+dfrac{5}{21}-dfrac{4}{23}+0,5+dfrac{16}{21}
b) dfrac{3}{7}.19dfrac{1}{3}-dfrac{3}{7}.33dfrac{1}{3}
c) left(15dfrac{1}{4}+2010right):left(-dfrac{5}{7}right)-left(25dfrac{1}{4}+2016right):left(-dfrac{5}{7}right)
d) left(2017-dfrac{3}{7}+dfrac{9}{11}right)-left(2016-dfrac{3}{7}+dfrac{8}{17}right)-left(2015+dfrac{9}{11}-dfrac{8}{17}right)
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Thực hiện phép tính:
a) \(1\dfrac{4}{23}+\dfrac{5}{21}-\dfrac{4}{23}+0,5+\dfrac{16}{21}\)
b) \(\dfrac{3}{7}.19\dfrac{1}{3}-\dfrac{3}{7}.33\dfrac{1}{3}\)
c) \(\left(15\dfrac{1}{4}+2010\right):\left(-\dfrac{5}{7}\right)-\left(25\dfrac{1}{4}+2016\right):\left(-\dfrac{5}{7}\right)\)
d) \(\left(2017-\dfrac{3}{7}+\dfrac{9}{11}\right)-\left(2016-\dfrac{3}{7}+\dfrac{8}{17}\right)-\left(2015+\dfrac{9}{11}-\dfrac{8}{17}\right)\)
8) \(\dfrac{17}{-26}.\left(\dfrac{1}{6}-\dfrac{5}{3}\right):\dfrac{17}{13}-\dfrac{20}{3}.\left(\dfrac{2}{5}-\dfrac{1}{4}\right)+\dfrac{2}{3}.\left(\dfrac{6}{5}-\dfrac{9}{2}\right)\)
a) dfrac{1}{3}-dfrac{3}{5}+dfrac{5}{7}-dfrac{7}{9}+dfrac{9}{11}-dfrac{11}{13}+dfrac{13}{15}+dfrac{11}{13}-dfrac{9}{11}+dfrac{7}{9}-dfrac{5}{7}+dfrac{3}{5}-dfrac{1}{3}
b)dfrac{1}{99}-dfrac{1}{99.98}-dfrac{1}{98.97}-dfrac{1}{97.96}-.....-dfrac{1}{3.2}-dfrac{1}{2.1}
c) dfrac{1}{1.3}+dfrac{1}{3.5}+.....+dfrac{1}{left(2n-1right)left(2n+1right)}+......+dfrac{1}{255.257}
Đọc tiếp
a) \(\dfrac{1}{3}-\dfrac{3}{5}+\dfrac{5}{7}-\dfrac{7}{9}+\dfrac{9}{11}-\dfrac{11}{13}+\dfrac{13}{15}+\dfrac{11}{13}-\dfrac{9}{11}+\dfrac{7}{9}\)\(-\dfrac{5}{7}+\dfrac{3}{5}-\dfrac{1}{3}\)
b)\(\dfrac{1}{99}-\dfrac{1}{99.98}-\dfrac{1}{98.97}-\dfrac{1}{97.96}-.....-\dfrac{1}{3.2}-\dfrac{1}{2.1}\)
c) \(\dfrac{1}{1.3}+\dfrac{1}{3.5}+.....+\dfrac{1}{\left(2n-1\right)\left(2n+1\right)}+......+\dfrac{1}{255.257}\)