Tính tổng S = \(\dfrac{1}{2}\) + \(\dfrac{2}{4}\) + \(\dfrac{3}{8}\) + \(\dfrac{4}{16}\) + ... + \(\dfrac{10}{2^{10}}\)
Thực hiện phép tính.(tính nhanh nếu có thể)
1/ \(2\dfrac{1}{3}.3\)
2/ \(\left(\dfrac{2}{5}-\dfrac{3}{4}\right)-\dfrac{2}{5}\)
3/ \(\dfrac{-10}{11}.\dfrac{4}{7}+\dfrac{-10}{11}.\dfrac{3}{7}+1\dfrac{10}{11}\)
Thực hiện các phép tính:
\(a,\left(\dfrac{7}{16}+\dfrac{-1}{8}+\dfrac{9}{32}\right):\dfrac{5}{4}\) \(b,10\dfrac{2}{9}+2\dfrac{3}{5}+6\dfrac{2}{9}\)
\(c,30\%-2\dfrac{2}{5}+0,2.\dfrac{1}{2}\) \(d,\dfrac{-25}{30}.\dfrac{37}{44}+\dfrac{-25}{30}.\dfrac{13}{44}+\dfrac{-25}{30}.\dfrac{-6}{44}\)
So sánh:
a/ \(A=\dfrac{17^{18}+1}{17^{19}+1};B=\dfrac{17^{17}+1}{17^{18}+1}\)
b/ \(A=\dfrac{10^8-2}{10^8+2};B=\dfrac{10^8}{10^8+4}\)
c/ \(A=\dfrac{20^{10}+1}{20^{10}-1};B=\dfrac{20^{10}-1}{20^{10}-3}\)
GIÚP MÌNH VỚI
a)chứng minh rằng :\(\dfrac{1}{3^2}\)+\(\dfrac{1}{4^2}\)+\(\dfrac{1}{5^2}\)+\(\dfrac{1}{6^2}\)........+\(\dfrac{1}{100^2}< \dfrac{1}{2}\)
b)tính nhanh tổng S với S= \(\dfrac{1}{3.5}+\dfrac{1}{5.7}+\dfrac{1}{7.9}+......+\dfrac{1}{61.63}\)
các cao nhân gải giúp với ạ !!! iem đang cần gấp
thực hiện phép tính
\(\dfrac{16}{103}\)+(38+\(\dfrac{-16}{103}\))
\(\dfrac{100}{91}\)+310+\(\dfrac{-9}{91}\)
\(\dfrac{-13}{49}\)+(\(\dfrac{-36}{49}\)+41)
\(\dfrac{-10}{71}\):1\(\dfrac{4}{71}\)
\(\dfrac{4}{15}\)+\(\dfrac{8}{15}\):2 -\(\dfrac{1}{18}\).\(\left(-3\right)^2\)
bài 1:thực hiện phiép tính
a)\(\dfrac{7}{4}\)+\(\dfrac{3}{2}\)+\(\dfrac{-9}{16}\)
b)\(\dfrac{-2}{7}\)+\(\dfrac{3}{5}\)+\(\dfrac{9}{7}\)+\(\dfrac{-18}{5}\)
c)\(\left\{-\dfrac{5}{13}\right\}\)+\(\dfrac{11}{10}\)-\(\dfrac{-9}{10}\)+\(\dfrac{-8}{13}\)
bài 2:tìm x biết
a)\(\dfrac{2}{9}\)-x=\(\dfrac{-5}{9}\)
b)x+\(\dfrac{-7}{13}\)=\(\dfrac{1}{2}\)
Tính Nhanh:
B=\(\dfrac{1}{2}\)+\(\dfrac{1}{4}\)+\(\dfrac{1}{8}\)+\(\dfrac{1}{16}\)+\(\dfrac{1}{32}\)+\(\dfrac{1}{64}\)
Giúp mình với mình cần gấp ạ
Bài 1. Tính
A= \(\left(8\dfrac{2}{7}-4\dfrac{2}{7}\right)-3\dfrac{4}{9}\)
B= \(\left(10\dfrac{2}{9}-6\dfrac{2}{9}\right)+2\dfrac{3}{5}\)
Bài 2. Tính
a) \(5\dfrac{1}{2}.3\dfrac{1}{4}\) b) \(6\dfrac{1}{3}:4\dfrac{2}{9}\) c) \(4\dfrac{3}{7}.2\)