G=6(6/1.7+6/7.13+6/13.19+..+6/n(n+6) )
=6(1-1/7+1/7-1/13+1/13-1/19+....+1/n-1/n+6)
=6(1-n/n+6)
=6.6/n+6
=36/n+6
vậy G=36/n+6
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Các câu hỏi tương tự
tìm x
\(X:\left(\frac{5}{1.7}+\frac{5}{7.13}+\frac{5}{13.19}+...+\frac{5}{601.607}\right)=0\)
Tính
a) A = \(\frac{2}{1.7}\)+\(\frac{2}{7.13}+\frac{2}{13.19}+...+\frac{2}{601.607}\)
giúp mik vs
Thực hiện phép tính:
a) \(A=\frac{5.\left(2^2.3^2\right)^9.\left(2^2\right)^6-2.\left(2^2.3\right)^{14}.3^4}{5.2^{28}.3^{18}-7.2^{29}.3^{18}}\)
b) \(B=81.\left[\frac{12-\frac{12}{7}-\frac{12}{289}-\frac{12}{85}}{4-\frac{4}{7}-\frac{4}{289}-\frac{4}{85}}:\frac{5+\frac{5}{13}+\frac{5}{169}+\frac{5}{91}}{6+\frac{6}{13}+\frac{6}{169}+\frac{6}{91}}\right].\frac{158158158}{711711711}\)
Giair giúp mik nha,cảm ơn các bạn nhìu.
Tính giá trị của các biểu thức sau:
\(C=\left(1+\frac{2}{3}\right).\left(1+\frac{2}{5}\right).\left(1+\frac{2}{7}\right)........\left(1+\frac{2}{2013}\right).\left(1+\frac{2}{2015}\right)\)
\(N=\frac{5.\left(2^2.3^2\right)^9.\left(2^2\right)^6-2.\left(2^2.3\right)^{14}.3^6}{5.2^{28}3^{19}-7.2^{29}.3^{18}}\)
Thực hiện phép tính:
A =\(\frac{5.\left(2^2.3^2\right)^9.\left(2^2\right)^6-2.\left(2^2.3\right)^{14}.3^4}{5.2^{28}.3^{18}-7.2^{29}.3^{18}}\)
B= \(81.\frac{12-\frac{12}{7}-\frac{12}{289}-\frac{12}{85}5+\frac{5}{13}+\frac{5}{169}+\frac{5}{91}}{4-\frac{4}{7}-\frac{4}{289}-\frac{4}{85}6+\frac{6}{13}+\frac{6}{169}+\frac{6}{91}}.\frac{158158158}{711711711}\)
Tínha)frac{5}{6}+6frac{5}{6}.(11frac{94}{1591}-6frac{38}{1517}):8frac{11}{43}b) 1frac{1}{6}+6frac{5}{6}.left(10frac{133}{2173}-5frac{23}{1643}right):41frac{12}{31}c)frac{0,8:left(frac{4}{5}.1,25right)}{0,64-frac{1}{25}}+frac{left(1,08-frac{2}{25}right):frac{4}{7}}{left(6frac{5}{9}-3frac{1}{4}right).2frac{2}{17}}-left(1,2.0,5right):frac{4}{5}
Đọc tiếp
Tính
a)\(\frac{5}{6}\)+\(6\frac{5}{6}\).(\(11\frac{94}{1591}-6\frac{38}{1517}\)):\(8\frac{11}{43}\)
b) \(1\frac{1}{6}+6\frac{5}{6}.\left(10\frac{133}{2173}-5\frac{23}{1643}\right):41\frac{12}{31}\)
c)\(\frac{0,8:\left(\frac{4}{5}.1,25\right)}{0,64-\frac{1}{25}}+\frac{\left(1,08-\frac{2}{25}\right):\frac{4}{7}}{\left(6\frac{5}{9}-3\frac{1}{4}\right).2\frac{2}{17}}-\left(1,2.0,5\right):\frac{4}{5}\)
Tính
\(D=\left(3-\frac{1}{4}+\frac{2}{3}\right)-\left(5+\frac{1}{3}-\frac{6}{5}\right)-\left(6-\frac{7}{4}+\frac{3}{2}\right)\)
Tính hợp lý:
a) \(\left(4\frac{2}{3}-2\frac{2}{5}+7\frac{7}{13}\right)-\left(3\frac{5}{23}-6\frac{6}{13}\right)\)
b) \(\frac{-17,5+\frac{5}{3}+2\frac{1}{7}}{7,0-\frac{2}{3}+\frac{6}{7}}\)
\(D=\frac{\left(2!\right)^2}{1^2}+\frac{\left(2!\right)^2}{3^2}+\frac{\left(2!\right)^2}{5^2}+\frac{\left(2!\right)^2}{7^2}+...+\frac{\left(2!\right)^2}{2015^2}\)
So sánh D với 6. Biết n! = 1.2.3....n ( n thuộc N )