a)\(A=\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right)\left(1-\frac{1}{5}\right)...\left(1-\frac{1}{20}\right)\)
\(A=\frac{1}{2}.\frac{2}{3}.\frac{3}{4}...\frac{19}{20}\)
\(A=\frac{1.2.3...19}{2.3.4...20}\)
\(A=\frac{1}{20}\)
\(\left(1-\frac{1}{2010}\right)\cdot\left(1-\frac{2}{2010}\right)\cdot\left(1-\frac{3}{2010}\right)\cdot....\cdot\left(1-\frac{2012}{2010}\right)\)
Bài 1: Tính a) \(\left(\frac{11}{12}:\frac{44}{16}\right)\cdot\left(\frac{-1}{3}+\frac{1}{2}\right)\) b) \(\frac{\left(-5^2\right)\cdot\left(-5\right)^3\cdot16}{5^4\cdot\left(-2\right)^4}\) c) \(7,5:\left(\frac{-5}{3}\right)+2\frac{1}{2}:\left(\frac{-5}{3}\right)\)d) \(\left(\frac{-1}{2}+\frac{1}{3}\right)\cdot\frac{4}{5}+\left(\frac{2}{3}+\frac{1}{2}\right):\frac{4}{5}\)
\(A=1+\frac{1}{2}\left(1+2\right)+\frac{1}{3}\left(1+2+3\right)+...+\frac{1}{2011}\left(1+2+3+...+2011\right)\)
1 TÍNH
\(a,\left(\frac{-1}{4}\right)^0\)
\(b,\left(-2\frac{1}{3}\right)^2\)
\(c,\left(\frac{4}{5}\right)^{-2}\)
\(d,\left(0,5\right)^{-3}\)
\(e,\left(-1\frac{1}{3}\right)^4\)
\(f,27^3:3^2\)
\(g,\left(\frac{3}{5}\right)^{15}:\left(\frac{9}{25}\right)^5\)
\(h,5-\left(-\frac{5}{11}\right)^0+\left(\frac{1}{3}\right)^2:3\)
\(i,\left(\frac{1}{3}\right)^{-3}+3.\left(\frac{1}{2}\right)^0+\left[\left(-2\right)^2:\frac{1}{2}\right].8\)
Bài 1:
1. Tính: \(E=1+\frac{1}{2}\left(1+2\right)+\frac{1}{3}\left(1+2+3\right)+\frac{1}{4}\left(1+2+3+4\right)+...+\frac{1}{200}\left(1+2+...+200\right)\)
2. Tìm và tính tổng các số nguyên x thỏa mãn: \(\frac{21}{5}\left|x\right|< 2019\)
3. Tìm x, biết: \(\frac{2^{24}\left(x-3\right)}{\left(3\frac{5}{7}-1,4\right)\left(6\cdot2^{24}-4^{13}\right)}=\left(\frac{5}{3}\right)^2\)
Bài 1 : Tính
1) \(\frac{4}{7}-\frac{1}{14}+\left|\frac{-5}{21}\right|\)
2) \(\left|\frac{-2}{3}\right|-\frac{1}{2}+3\)
3) \(\left|\frac{7}{-4}\right|-\frac{5}{8}+\frac{-2}{3}\)
4) \(\frac{4}{5}+\left|\frac{-3}{2}\right|+\frac{1}{-4}\)
5) \(\left|\frac{-1}{4}\right|-3+\frac{3}{4}\)
6) \(\left|\frac{-1}{3}\right|-\frac{5}{4}+\frac{1}{5}\)
Bài 2 : Tìm x, biết :
1) \(x-\left|1\frac{1}{6}\right|=\frac{5}{21}\)
2) \(x+\left|-1\frac{2}{3}\right|=\left|-\frac{3}{4}\right|\)
3) \(\left|x-\frac{1}{3}\right|=\frac{5}{2}\)
4) \(\left|x+\frac{2}{3}\right|=0\)
5) \(\left|x+2\right|=\frac{1}{3}-\frac{1}{5}\)
6) \(\left|x-4\right|=\frac{1}{5}-\left(\frac{1}{2}-\frac{5}{4}\right)\)
7) \(\left|x-\frac{5}{4}\right|=-\frac{1}{3}\)
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E cần gấp lắm ạ, cảm ơn.
Bài 1 : Tính
1) \(\frac{4}{7}-\frac{1}{14}+\left|\frac{-5}{21}\right|\)
2) \(\left|\frac{-2}{3}\right|-\frac{1}{2}+3\)
3) \(\left|\frac{7}{-4}\right|-\frac{5}{8}+\frac{-2}{3}\)
4) \(\frac{4}{5}+\left|\frac{-3}{2}\right|+\frac{1}{-4}\)
5) \(\left|\frac{-1}{4}\right|-3+\frac{3}{4}\)
6) \(\left|\frac{-1}{3}\right|-\frac{5}{4}+\frac{1}{5}\)
Bài 2 : Tìm x, biết :
1) \(x-\left|1\frac{1}{6}\right|=\frac{5}{21}\)
2) \(x+\left|-1\frac{2}{3}\right|=\left|-\frac{3}{4}\right|\)
3) \(\left|x-\frac{1}{3}\right|=\frac{5}{2}\)
4) \(\left|x+\frac{2}{3}\right|=0\)
5) \(\left|x+2\right|=\frac{1}{3}-\frac{1}{5}\)
6) \(\left|x-4\right|=\frac{1}{5}-\left(\frac{1}{2}-\frac{5}{4}\right)\)
7) \(\left|x-\frac{5}{4}\right|=-\frac{1}{3}\)
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E đang cần gấp, cảm ơn :)
Bài 2 : Tìm x, biết :
1) \(x-\left|1\frac{1}{6}\right|=\frac{5}{21}\)
2) \(x+\left|-1\frac{2}{3}\right|=\left|-\frac{3}{4}\right|\)
3) \(\left|x-\frac{1}{3}\right|=\frac{5}{2}\)
4) \(\left|x+\frac{2}{3}\right|=0\)
5) \(\left|x+2\right|=\frac{1}{3}-\frac{1}{5}\)
6) \(\left|x-4\right|=\frac{1}{5}-\left(\frac{1}{2}-\frac{5}{4}\right)\)
7) \(\left|x-\frac{5}{4}\right|=-\frac{1}{3}\)
\(a,1\frac{13}{15}.0,75-\left(\frac{8}{15}+0,25\right).\frac{24}{47}\)
\(b,5:\left(4\frac{3}{4}-1\frac{25}{28}\right)-1\frac{3}{8}:\left(\frac{3}{8}+\frac{9}{20}\right)\)
\(c,6\frac{5}{12}:2\frac{3}{4}+11\frac{1}{4}.\left(\frac{1}{3}-\frac{1}{5}\right)\)
\(d,\left(\frac{3}{5}+0,415-\frac{3}{200}\right).2\frac{2}{3}.0,25\)
\(e,\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)
\(g,1\frac{13}{15}.0,75-\left(\frac{11}{20}+25\%\right);\frac{7}{3}\)
