\(M=\frac{1.2.3.4.5...98.99}{10}\)
\(M=1.2.3.4.5.6.7.8.9.11.12...98.99\)
\(M=\frac{1.2.3.4.5...98.99}{10}\)
\(M=1.2.3.4.5.6.7.8.9.11.12...98.99\)
Tính:
\(A=\frac{1+\frac{1}{3}+\frac{1}{5}+\frac{1}{7}+.....\frac{1}{97}+\frac{1}{99}}{\frac{1}{1\times99}+\frac{1}{3\times97}+\frac{1}{5\times95}+\frac{1}{97\times3}+\frac{1}{99\times1}}\)
Có khó không giúp mình với chiều nay cần gấp
Tim X .
Cau 1 : x : ( \(\frac{1}{1\times3}\) + \(\frac{1}{3\times5}\) + ...... + \(\frac{1}{101\times103}\)) = 1
Cau 2 : (\(\frac{1}{1\times2}\) + \(\frac{1}{2\times3}\) + \(\frac{1}{3\times4}\) + ......... + \(\frac{1}{11\times12}\) ) \(\times\) X = 2
cac ban giup minh nha. Minh dang can gap
Tìm x :
a. x : \(\frac{3}{4}\) = 2x \(\times\) \(\frac{7}{3}\) + 5
b. 3x - 2 = 5x - 4
c. ( \(\frac{1}{1\times2}\)+ \(\frac{1}{2\times3}\)+ \(\frac{1}{3\times4}\)+ .... + \(\frac{1}{11\times12}\) ) \(\times\) x = 2
d. x : ( \(\frac{1}{1\times3}\) + \(\frac{1}{3\times5}\) + ..... + \(\frac{1}{101\times103}\) ) = 1
\(\frac{1}{1\times2}+\frac{1}{2\times3}+\frac{1}{3\times4}+...+\frac{1}{x.\left(x+1\right)}\)
Tính tổng
M = \(\frac{1}{4\times6}+\frac{1}{8\times9}+\frac{1}{12\times12}+......+\frac{1}{2680\times2013}\)
Giúp mk nhé Mai
Mấy bạn giúp mình với
Bài 1:Chứng minh rằng:
a)\(\frac{1}{1}-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{9}-\frac{1}{10}=\frac{1}{6}+\frac{1}{7}+\frac{1}{8}+\frac{1}{9}+\frac{1}{10}\)
b)\(\frac{1}{1\times2}+\frac{1}{3\times4}+\frac{1}{5\times6}+...+\frac{1}{400}=\frac{1}{201}+\frac{1}{202}+...+\frac{1}{400}\)
Tinh
\(\frac{\left(3\times4\times2^{16}\right)^2}{11\times2^{13}\times4^{11}-16^9}\)
Tính nhanh :
\(18\times24+18\times128-36-36\times5-20\times9\)
tính hợp lí nếu có thể
\(-\frac{1}{4}\times13\frac{9}{11}-0,25\times6\frac{2}{11}\)
\(B=\frac{-5}{6}\times\frac{4}{19}+\frac{-7}{12}\times\frac{4}{19}-\frac{40}{57}\)
\(\frac{3}{7}\times\frac{9}{26}-\frac{1}{14}\times\frac{1}{13}-\frac{1}{7}\)
\(\frac{4}{9}:\left(-\frac{1}{7}\right)+6\frac{5}{9}:\left(-\frac{1}{7}\right)\)