Các câu hỏi tương tự
1, Tính \(\frac{1}{2}-\left(\frac{1}{3}+\frac{2}{3}\right)+\left(\frac{1}{4}+\frac{2}{4}+\frac{3}{4}\right)-\left(\frac{1}{5}+\frac{2}{5}+\frac{3}{5}+\frac{4}{5}\right)+...+\left(\frac{1}{100}+\frac{2}{100}+\frac{3}{100}+...+\frac{99}{100}\right)\)2,Tính \(\left(1-\frac{1}{2^2}\right)x\left(1-\frac{1}{3^2}\right)x\left(1-\frac{1}{4^2}\right)x...x\left(1-\frac{1}{n^2}\right)\)
Tính nhanh:
A = \(\left(\frac{1}{4}-1\right).\left(\frac{1}{9}-1\right).\left(\frac{1}{16}-1\right).\left(\frac{1}{25}-1\right)......\left(\frac{1}{121}-1\right)\)
a) Tính
\(A=\left(1-\frac{1}{2}\right)\cdot\left(1-\frac{1}{3}\right)\cdot\left(1-\frac{1}{4}\right)\cdot\cdot\cdot\left(1-\frac{1}{2014}\right)\cdot\left(1-\frac{1}{2015}\right)\cdot\left(1-\frac{1}{2016}\right)\)
b) Tìm x:
\(\frac{x-2}{12}+\frac{x-2}{20}+\frac{x-2}{30}+\frac{x-2}{42}+\frac{x-2}{56}+\frac{x-2}{72}=\frac{16}{9}\)
\(\frac{1}{\left(x+2\right)\left(x+3\right)}+\frac{1}{\left(x+3\right)\left(x+4\right)}+\frac{1}{\left(x+4\right)\left(x+5\right)}+\frac{1}{\left(x+5\right)\left(x+6\right)}=\frac{1}{8}\)
1/ Tính tổng:M frac{1}{2}+frac{1}{6}+frac{1}{12}+frac{1}{20}+frac{1}{30}+frac{1}{42}2/Tìm X:frac{1}{21}+frac{1}{28}
+frac{1}{36}
+.....+frac{2}{x.left(x+1right)}frac{2}{9}3/Tính tích sau rồi tìm số nghịch đảo của kết quả:Tleft(1-frac{1}{3}right)left(1-frac{1}{5}right)left(1-frac{1}{7}right)left(1-frac{1}{9}right)left(1-frac{1}{11}right)left(1-frac{1}{2}right)left(1-frac{1}{4}right)left(1-frac{1}{6}right)left(1-frac{1}{8}right)left(1-frac{1}{10}right)4/ TÍnh giá trị của biểu thức:frac{1^2}{1.2}.f...
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1/ Tính tổng:
M =\(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}\)
2/Tìm X:
\(\frac{1}{21}+\frac{1}{28} +\frac{1}{36} +.....+\frac{2}{x.\left(x+1\right)}=\frac{2}{9}\)
3/Tính tích sau rồi tìm số nghịch đảo của kết quả:
\(T=\left(1-\frac{1}{3}\right)\left(1-\frac{1}{5}\right)\left(1-\frac{1}{7}\right)\left(1-\frac{1}{9}\right)\left(1-\frac{1}{11}\right)\left(1-\frac{1}{2}\right)\left(1-\frac{1}{4}\right)\left(1-\frac{1}{6}\right)\left(1-\frac{1}{8}\right)\left(1-\frac{1}{10}\right)\)
4/ TÍnh giá trị của biểu thức:
\(\frac{1^2}{1.2}.\frac{2^2}{2.3}.\frac{3^2}{3.4}\frac{4^2}{4.5}\)
Tìm x biết: \(\left(x+\frac{1}{2}\right)+\left(x+\frac{1}{4}\right)+\left(x+\frac{1}{8}\right)+\left(x+\frac{1}{16}\right)=1\)
tính
\(K=\left(\frac{1}{4}-1\right).\left(\frac{1}{9}-1\right).\left(\frac{1}{16}-1\right).\left(\frac{1}{25}-1\right).\left(\frac{1}{36}-1\right).\left(\frac{1}{49}-1\right).\left(\frac{1}{64}-1\right).\left(\frac{1}{81}-1\right).\left(\frac{1}{100}-1\right)\)
bài 1: Tính bằng cách hợp lí1)frac{11}{3}:3frac{1}{3}-32)frac{5}{6}:frac{3}{52}-frac{5}{6}.47frac{1}{3}3)left(9frac{3}{4}:frac{26}{5}+frac{17}{5}.2frac{7}{34}right):left(-1frac{9}{16}right)4)left(frac{1}{2}-1right).left(frac{1}{3}-1right)...left(frac{1}{2002}-1right).left(frac{1}{2003}-1right)5)left(1-frac{1}{21}right).left(1-frac{1}{28}right).left(1-frac{1}{36}right)...left(1-frac{1}{1326}right)bài 2: tìm x :1)left(frac{2x}{3}-3right):left(-10right)frac{2}{5}2)left(x+frac{1}{5}right)left(x-frac...
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bài 1: Tính bằng cách hợp lí
1)\(\frac{11}{3}:3\frac{1}{3}-3\)
2)\(\frac{5}{6}:\frac{3}{52}-\frac{5}{6}.47\frac{1}{3}\)
3)\(\left(9\frac{3}{4}:\frac{26}{5}+\frac{17}{5}.2\frac{7}{34}\right):\left(-1\frac{9}{16}\right)\)
4)\(\left(\frac{1}{2}-1\right).\left(\frac{1}{3}-1\right)...\left(\frac{1}{2002}-1\right).\left(\frac{1}{2003}-1\right)\)
5)\(\left(1-\frac{1}{21}\right).\left(1-\frac{1}{28}\right).\left(1-\frac{1}{36}\right)...\left(1-\frac{1}{1326}\right)\)
bài 2: tìm x :
1)\(\left(\frac{2x}{3}-3\right):\left(-10\right)=\frac{2}{5}\)
2)\(\left(x+\frac{1}{5}\right)\left(x-\frac{2}{7}\right)< 0\)
mách mình với mấy cái kia là hỗn số nha
Tìm x, biết :
a) \(\left(\frac{3}{4}.x-\frac{9}{16}\right).\left(\frac{1}{3}+\frac{-3}{5}:x\right)=0\)
b) \(\left(x-\frac{1}{3}\right).\left(x+\frac{2}{5}\right)>0\)
c) \(\left(x+\frac{3}{5}\right).\left(x+1\right)< 0\)