Chứng tỏ rằng:
\(T=\frac{1}{2^2}+\frac{1}{4^2}+\frac{1}{6^2}+\frac{1}{8^2}+\frac{1}{10^2}+\frac{1}{12^2}+\frac{1}{14^2}< \frac{1}{2}\)
GIÚP MIK VS MN ƯI,CHI TIẾT SẼ ĐC K NHA
a) \(\frac{14}{21}+1-|\frac{1}{3}-1|\)
b) \(\frac{1}{3}-|\frac{-1}{4}+\frac{5}{6}|-|\frac{-7}{12}|\)
c) \(|\frac{-5}{6}+\frac{1}{2}|-\frac{1}{3}+|\frac{-5}{12}|\)
d) \(\frac{-10}{6}-\frac{4}{-8}|\frac{-3}{4}+\frac{5}{-2}|\)
e) \(|\frac{-5}{2}|-|\frac{-4}{28}+1|-\frac{-3}{14}\)
g) \(\frac{5}{7}-|\frac{-4}{28}+\frac{1}{2}|-|\frac{-3}{14}|\)
Các bạn giúp mik bài này nhé. Càm ơn nhiều
Tính:
\(S=\left(\frac{1}{2}\right)^2+\left(\frac{1}{4}\right)^2+\left(\frac{1}{6}\right)^2+\left(\frac{1}{8}\right)^2+\left(\frac{1}{10}\right)^2+\left(\frac{1}{12}\right)^2+\left(\frac{1}{14}\right)^2\)
3.Tính hợp lí:
a,\(\frac{17}{5}.\frac{-31}{125}.\frac{1}{2}.\frac{10}{17}.\frac{-1}{2^3}\)
b,\(\left(\frac{11}{4}.\frac{5}{9}-\frac{4}{9}.\frac{11}{4}\right).\frac{8}{33}\)
c,\(\left(\frac{17}{28}+\frac{18}{29}-\frac{19}{30}-\frac{20}{31}\right).\left(\frac{-5}{12}+\frac{1}{4}+\frac{1}{6}\right)\)
4.Tìm tích:
a,\(\left(\frac{1}{2}+1\right)\left(\frac{1}{3}+1\right).....\left(\frac{1}{99}+1\right)\)
b,\(\left(\frac{1}{2}-1\right)\left(\frac{1}{3}-1\right).....\left(\frac{1}{100}-1\right)\)
c,\(\frac{3}{2^2}.\frac{8}{3^2}.\frac{15}{4^2}....\frac{899}{30^2}\)
AI CÒN THỨC THÌ GIÚP MIK VS,MIK ĐANG CẦN GẤP
Hãy giúp tôi giải phép tính này:
So sánh:
\(\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+\frac{1}{5^2}+\frac{1}{6^2}+\frac{1}{7^2}+\frac{1}{8^2}+\frac{1}{9^2}+\frac{1}{10^2}+\frac{1}{11^2}\)với\(\frac{5}{12}\)
thực hiện các phép tính sau:
\(a,\left(4\frac{5}{37}-3\frac{4}{5}+8\frac{15}{29}\right)-\left(3\frac{5}{37}-6\frac{14}{29}\right)\)
\(b,\left(2\frac{5}{6}+1\frac{4}{9}\right):\left(10\frac{1}{12}-9\frac{1}{2}\right)\)
\(c,-\frac{2}{3}\left(8\frac{1}{2}-7.75\right):\frac{1}{3}+0.125:2\frac{2}{3}\)
\(\frac{1}{11^2}+\frac{1}{12^2}+\frac{1}{13^2}+\frac{1}{14^2}+...+\frac{1}{100^2}< \frac{1}{10}\). Ai làm đúng nhất mình tích cho.
Bài 3 : a) Tính
\(\frac{\left(13\frac{1}{4}-2\frac{5}{27}-10\frac{5}{6}\right)\cdot230\frac{1}{25}+46\frac{3}{4}}{\left(1\frac{3}{10}+\frac{10}{3}\right):\left(12\frac{1}{3}-14\frac{2}{7}\right)}\)
b) Tính :
\(P=\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2012}}{\frac{2011}{1}+\frac{2010}{2}+\frac{2009}{3}+\frac{1}{2011}}\)
Tính
\(\frac{\left(13\frac{1}{4}-2\frac{5}{27}-10\frac{5}{6}\right).230\frac{1}{25}+46\frac{3}{4}}{\left(1\frac{3}{7}+\frac{10}{3}\right):\left(12\frac{1}{3}-14\frac{2}{7}\right)}\)
Ai làm nhanh đúng mk tick nha !