Tính
\(\frac{18.275+3.666+}{1+4+7+...+58+61+62.3+62.4-271}\) \(\frac{9.614,2}{71}\)
Những câu hỏi liên quan
N=\(\frac{18.275+3.666+}{1+4+7+58+61+62.2+62.3+62.4-271}\)\(\frac{9.614,2}{71}\)
Tính nhanh D=\(\frac{18.275+3.666+9.614.2}{1+4+7+...+58+61+62+62.2+62.3+62.4-271}\)
N= \(\frac{18x275+3x666+9x614x2}{1+4+7+...+58+61+62+62x2+62x3+62x4-271}\)
Phân tích thành nhân tử:frac{1}{27}x^{3}-frac{1}{6}x^{2}+frac{1}{4}x-frac{1}{8}271x3−61x2+41x−81
Đọc tiếp
Phân tích thành nhân tử:
\frac{1}{27}x^{3}-\frac{1}{6}x^{2}+\frac{1}{4}x-\frac{1}{8} =
Tính nhanh:a) N frac{18times275+3times666+9times614times2}{1+4+7+...+58+61+62+62times2+62times3+62times4-271}.b) M( 1- frac{1}{3})x( 1- frac{1}{6})x( 1- frac{1}{10})x( 1- frac{1}{10})x( 1- frac{1}{15})x( 1- frac{1}{21})x( 1- frac{1}{28}).N( frac{6}{8}+ 1)x( frac{6}{18}+ 1)x( frac{6}{30}+ 1)x...x( frac{6}{10100}+ 1).
Đọc tiếp
Tính nhanh:
a) N= \(\frac{18\times275+3\times666+9\times614\times2}{1+4+7+...+58+61+62+62\times2+62\times3+62\times4-271}\).
b) M=( 1- \(\frac{1}{3}\))x( 1- \(\frac{1}{6}\))x( 1- \(\frac{1}{10}\))x( 1- \(\frac{1}{10}\))x( 1- \(\frac{1}{15}\))x( 1- \(\frac{1}{21}\))x( 1- \(\frac{1}{28}\)).
N=( \(\frac{6}{8}\)+ 1)x( \(\frac{6}{18}\)+ 1)x( \(\frac{6}{30}\)+ 1)x...x( \(\frac{6}{10100}\)+ 1).
Tính bằng cách thuận tiện
1,\(\frac{13}{19}\left(\frac{19}{26}-\frac{71}{43}\right)+\frac{71}{43}\left(\frac{13}{19}-\frac{86}{71}\right)\)
2,\(\frac{5}{7}\left(\frac{1}{2}-\frac{1}{3}+\frac{4}{7}\right)+\left(\frac{1}{2}-\frac{1}{3}-\frac{4}{7}\right):\frac{7}{5}\)
Tính một cách hợp lí: \(1,2.\frac{{15}}{4} + \frac{{16}}{7}.\frac{{ - 85}}{8} - 1,2.5\frac{3}{4} - \frac{{16}}{7}.\frac{{ - 71}}{8}\)
\(\begin{array}{l}1,2.\frac{{15}}{4} + \frac{{16}}{7}.\frac{{ - 85}}{8} - 1,2.5\frac{3}{4} - \frac{{16}}{7}.\frac{{ - 71}}{8}\\ =(1,2.\frac{{15}}{4} - 1,2.5\frac{3}{4}) +( \frac{{16}}{7}.\frac{{ - 85}}{8}- \frac{{16}}{7}.\frac{{ - 71}}{8}) \\= \frac{{12}}{{10}}.\frac{{15}}{4} - \frac{{12}}{{10}}.\frac{{23}}{4} + \frac{{16}}{7}.\frac{{ - 85}}{8} - \frac{{16}}{7}.\frac{{ - 71}}{8}\\ = \frac{6}{5}.\frac{{15}}{4} - \frac{6}{5}.\frac{{23}}{4} + \frac{{16}}{7}.\frac{{ - 85}}{8} + \frac{{16}}{7}.\frac{{71}}{8}\\ = \frac{6}{5}.(\frac{{15}}{4} - \frac{{23}}{4}) + \frac{{16}}{7}.(\frac{{ - 85}}{8} + \frac{{71}}{8})\\ = \frac{6}{5}.\frac{{ - 8}}{4} + \frac{{16}}{7}.\frac{{ - 14}}{8}\\ = \frac{6}{5}.( - 2) + ( - 4)\\ = \frac{{ - 12}}{5} + \frac{{ - 20}}{5}\\ = \frac{{ - 32}}{5}\end{array}\)
Chú ý: Nếu phân số chưa tối giản, ta nên tối giản phân số trước để việc tính toán được thuận tiện hơn.
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Tính D = \(\frac{1}{2}-\frac{1}{2^4}+\frac{1}{2^7}-\frac{1}{2^{10}}+...-\frac{1}{2^{58}}\)
\(\frac{1}{2^3}\)D= \(\frac{1}{2^4}-\frac{1}{2^7}+\frac{1}{2^{10}}-\frac{1}{2^{13}}+...+\frac{1}{2^{58}}-\frac{1}{2^{61}}\)
D+ \(\frac{1}{2^3}\)D=\(\frac{1}{2}-\frac{1}{2^4}+\frac{1}{2^4}+\frac{1}{2^7}-\frac{1}{2^7}-\frac{1}{2^{10}}+\frac{1}{2^{10}}+...-\frac{1}{2^{58}}+\frac{1}{2^{58}}-\frac{1}{2^{61}}\)
\(\frac{9}{8}\)D= \(\frac{1}{2}-\frac{1}{2^{61}}\)=> D= \(\frac{\frac{1}{2}-\frac{1}{2^{61}}}{\frac{9}{8}}\)
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Tính D, biết
D=\(\frac{1}{2}-\frac{1}{2^4}+\frac{1}{2^7}-\frac{1}{2^{10}}+........-\frac{1}{2^{58}}\)
\(D=\frac{1}{2}-\frac{1}{2^4}+\frac{1}{2^7}-\frac{1}{2^{10}}+...+\frac{1}{2^{55}}-\frac{1}{2^{58}}\)
\(\Rightarrow2^3D=2^2-\frac{1}{2}+\frac{1}{2^4}-\frac{1}{2^7}+....+\frac{1}{2^{52}}-\frac{1}{2^{55}}\)
\(\Rightarrow8D+D=2^2-\frac{1}{2^{58}}\)
\(\Rightarrow D=\frac{2^2-\frac{1}{2^{58}}}{9}\)
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