1/7B=5/2.7+4/7.11+3/11.14+1/14.15+13/15.28
1/7B=1/2-1/7+1/7-1/11+1/11-1/14+1/14-1/15+1/15-1/28
1/7B=1/2-1/28
B=(1/2-1/28):1/7
1/7B=5/2.7+4/7.11+3/11.14+1/14.15+13/15.28
1/7B=1/2-1/7+1/7-1/11+1/11-1/14+1/14-1/15+1/15-1/28
1/7B=1/2-1/28
B=(1/2-1/28):1/7
\(B=\frac{5}{2\times1}+\frac{4}{1\times11}+\frac{3}{11\times2}+\frac{1}{2\times15}+\frac{13}{15\times4}\)
\(\frac{5}{2\times1}+\frac{4}{1\times11}+\frac{3}{11\times3}+\frac{1}{2\times15}+\frac{13}{15\times4}\)
giúp mình với
\(\frac{3}{8\times11}+\frac{4}{11\times15}+\frac{5}{15\times20}+\frac{6}{20\times26}+\frac{7}{26\times33}+\frac{8}{33\times41}+\frac{9}{41\times50}=\frac{2}{5}-2\times x\)
Bài 4: Tính nhanh:
a, A =\(\left(\frac{84}{13}\right)^2+\left(\frac{35}{13}\right)^2\)
b, B = \(\frac{12-\frac{12}{7}-\frac{12}{289}-\frac{12}{85}}{4-\frac{4}{7}-\frac{4}{289}-\frac{4}{85}}\div\frac{3+\frac{3}{13}+\frac{3}{169}+\frac{3}{91}}{7+\frac{7}{13}+\frac{7}{169}+\frac{7}{91}}\)
c, C =\(\frac{1\times2+2\times4+3\times6+4\times8+5\times10}{3\times4+6\times8+9\times12+12\times16+15\times20}\)
Rút gọn
a) \(\frac{60}{-150}\) B) \(\frac{-84}{-126}\) c)\(\frac{6\times11-60}{6\times30}\) d) \(\frac{2^3\times4^5\times3^2}{2\times1\times4\times18}\)
Thực hiện phép tính:
a)\(1\times2\times3\times......\times9-1\times2\times3\times......\times8-1\times2\times3\times.....\times8\times8\)
b)\(B=\frac{\left(3\times4\times2^{16}\right)^2}{11\times2^{13}\times4^{11}-16^9}\)
c)\(C=70\times\left(\frac{131313}{565656}+\frac{131313}{727272}+\frac{131313}{909090}\right)\)
d)\(B=\frac{1}{4\times9}+\frac{1}{9\times14}+\frac{1}{14\times19}+...+\frac{1}{64\times69}\)
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tính tổng :\(B=\frac{5}{1\times2}+\frac{13}{2\times3}+\frac{25}{3\times4}+\frac{41}{4\times5}+...+\frac{181}{9\times10}\)
\(B=\frac{\frac{3}{5}+\frac{3}{7}-\frac{1}{3}+\frac{3}{11}}{\frac{6}{5}+\frac{6}{7}-\frac{2}{3}+\frac{6}{11}}+\frac{\left(\frac{1}{4}-\frac{1}{5}-\frac{1}{20}\right)\times2021}{\frac{1}{1\times2}+\frac{1}{2\times3}+\frac{1}{3\times4}+...+\frac{1}{99\times100}}\) Giá trị của B là:(cho mình cách giải chi tiết nhé mình sẽ tick)
Tinh hop ly cac bieu thuc sau
a. \(A=\frac{3^{10}\times11+3^{10}\times5}{3^9\times2^4}\)
\(C=\frac{11\times3^{22}\times3^7-9^{15}}{\left(2\times3^{14}\right)^2}\)