Tính nhanh:(7/9+1)(7/20+1)(7/33+1)....(7/10800+1)
tính nhanh ;A=(7/9+1)(7/20+1)(7/33+1)....(7/10800+1)
tinh nhanh A=(7/9+1)(7/20+1)(7/33+1).....(7/10800+1)
Tính nhanh:
C=\(\left(\frac{7}{9}+1\right)\left(\frac{7}{20}+1\right)\left(\frac{7}{33}+1\right).......\left(\frac{7}{10800}+1\right)\)
tính nhanh A= \(\left(\frac{7}{9}+1\right).\left(\frac{7}{20}+1\right).\left(\frac{7}{33}+1\right)....\left(\frac{7}{10800}+1\right)\)
Tính nhanh:
C=( \(\frac{7}{9}\)+ 1)( \(\frac{7}{20}\)+ 1)( \(\frac{7}{33}\)+ 1).....( \(\frac{7}{10800}\)+ 1).
\(C=\left(\frac{7}{9}+1\right)\left(\frac{7}{20}+1\right)\left(\frac{7}{33}+1\right)...\left(\frac{7}{10800}+1\right)\)
\(=\frac{16}{9}.\frac{27}{20}.\frac{40}{33}.....\frac{10807}{10800}\)
\(=\frac{2.8}{1.9}.\frac{3.9}{2.10}.\frac{4.10}{3.11}.....\frac{101.107}{100.108}\)
\(=\frac{2.3.4....101}{1.2.3....100}.\frac{8.9.10...107}{9.10.11...108}\)
\(=101.\frac{2}{27}\)\(=\frac{202}{27}\)
Tính:
\(C=\left(\frac{7}{9}+1\right)\left(\frac{7}{20}+1\right)\left(\frac{7}{33}+1\right)...\left(\frac{7}{10800}+1\right)\)
Tính nhanh
a,1.2.3+2.3.4+...+2014.2015.2016
B,(7/9+1).(7/20+1)....(7/10800+1)
Tính nhanh :
A = ( 1 + 7/9 ).(1+7/20).(1+7/33 )....( 1 + 7/2900 )
1) Tính:\(A=3-\frac{1}{2}-\frac{1}{6}-\frac{1}{12}-\frac{1}{20}-\frac{1}{30}-\frac{1}{42}-\frac{1}{56}\)
2) Tìm tất cả các số nguyên tố x,y sao cho x2 - 6y2 - 1 = 0
3) Cho \(n\in N\)biết n-10; n+4. n+60 đều là số nguyên tố. CMR: n+90 là số nguyên tố
4) Tính nhanh
\(A=\left(\frac{7}{9}+1\right)\left(\frac{7}{20}+1\right)\left(\frac{7}{33}+1\right).....\left(\frac{7}{10800}+1\right)\)
Các bn giúp mk nhanh lên nhé
\(A=3-\frac{1}{2}-\frac{1}{6}-\frac{1}{12}-\frac{1}{20}-\frac{1}{30}-\frac{1}{42}-\frac{1}{56}\)
\(A=3-\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}+\frac{1}{56}\right)\)
\(A=3-\left(\frac{1}{1\cdot2}+\frac{1}{2\cdot3}+\frac{1}{3\cdot4}+\frac{1}{4\cdot5}+\frac{1}{5\cdot6}+\frac{1}{6\cdot7}+\frac{1}{7\cdot8}\right)\)
\(A=3-\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}+\frac{1}{7}-\frac{1}{8}\right)\)
\(A=3-\left(1-\frac{1}{8}\right)\)
\(A=3-\frac{5}{8}\)
\(A=\frac{19}{8}\)